Report of experiments upon the animal heat of fishes, made at Provincetown, Mass., during the summer of 1879, in connection with operations of the United States Fish Commission

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306 PROCEEDINGS OF UNITED

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REPORT OF

KXPERTMEIVTii*UPOIV

THE

AIVIITIAI.

HEAT OF

FISHES,

mADE AT

PROVirvCETOU^IV, MASS.,

DURINO THE

8U1?II?IER

OF

1S>9, IIV COIV:VE«JTIOIV

WITH OPERATIONS OF THE

riVITED

STATES FISH

COlUiniSSIOiX.

By

J.

H. KIDDER,

Surg^eon, IT.S. IVAVY.

Sir:

The

investigation ofthe manifestationofanimal heatbyfishes, withwhich you intrusted

me

last summer, having been brought toa pauseforthe time beingbythe close oftheFish Commission's

summer

work,I submit the following report of

my

experiments,so far as they have gone,with adescription oftheinstruments usedandthe

mode

of observation.

But

littleinthe

way

of actualexperimentrelating to this interesting question seems tohavebeen donebyother observers than thosecon- nectedwith the Fish Commission, although numerousallusions tothe remarkableadaptability offishestoextremesoftemperature,andocca- sionalrecordsof moreorless incomplete experiments,are tobefound scatteredthroughscientific literature.

A

complete bibliographyofthese fragmentary noteswouldbevoluminousandofquestionablevalue,but ashortaccountofsuch observationsasIhavebeenable to finda record

of,eitherinteresting in themselvesorof incidental value as throwing lightupontheinvestigation,isappendedto this report.

So faras I have been able to learn, all ofthe observations

made

hithertouponthetemperatureoffisheshavebeen confinedto theintes- tinal canal,thethermometerbeing passedintotherectumoroesophagus, as is the usual practice inobservationsupon thebodytemperatureof mammals. Buttheconditions areby no meansthe same. Theintesti- nal canalofafishisthinandscarcelymuscular5 the walls oftheabdo-

men

are also thin,and sosparingly vascularthat noblood flows

when

theyarecutthrough; andconsequently,always surroundedastheyare bywater, against the chillingeffectofwhichthere is nosufficient pro- tection, it is byno means in the rectum orstomach that

we

should reasonably look forthe bodytemperatureofafish. In pointoffact, the experimentstobehereinafter detailedshowclearlyenoughthatthe rectum temperatureofafreshly-taken fish rarelyexceeds that ofthe waterinwhichitswims byso

much

asa degree(Fahrenheit). Sothat

it

may

bequite safelytakenasan indextothelattertemperature

when

thereisnodeep-seathermometerathand.

Anotherpointtobeconsideredisthe fact thatthegillsofmostfishes floatfreely inthesurroundingwater,andthatalloftheblood in each individualnuist,inpassingthroughthese organs,bespread outsoas to expose the greatest possible surface tothechilling effectofthewater quitelongenoughtoreduceittothesametemperature.

From

thelow organizationoffishes,andfrom thesimplicity of their digestive and circidatory functions, considered together with thefact

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that theirblooditselfischilledbycloseproximity with the surrounding waterat leastonce ineachcircuit,and that thus theoxidation of the blood, soimportant a sourceof animal heatin mammals,isquite neu- tralized,

we

ought not to expectso great adifference in temperature betweenthebloodofafish and thewaterinwhichitswimsasobtains betweenthebloodof

mammals

and the surrounding medium,nor that thelimitswithinwhichitsnormaltemperaturemustbeconfinedshould besonarrow.

And,whileitisdifficulttobelievethat the chemical changes necessary to the nutrition,waste,and repair of the body of a fish, taken togetherwith its active muscular movements,can go on without the evolution ofalargeamountofanimal heat; itisalso plain that

we

are nottoexpecttofindthe manifestation of thisheateither intheintesti- nalcanal,amereosmotic tube for the passageand absorption ofthe food, scarcelyvascularandbarely separatedfromthesurrounding water bythe thin bloodless walls ofthe

abdomen

;norinthearterialbloodre- turningfrom the gills,chilled

down

to the temperature of the water withwhichithasjustbeeninintimatecontact.

We

should expectto findthebloodofafishatitswarmest afterhav- ingbeendistributed tothesubstanceofthebody,havingfurnished the materialfor nutrition,takenup theresults of waste,and received the heat developedbytheseprocesses and bythe conversion ofmuscular motion;thatisto say, intheheartandbranchialartery.

The

experiments to be described have been tentative for themost part,andaccordingly temperatures havebeen takenintherectum, the stomach, variousparts ofthemuscular tissue,thelargevenoustrunks, thecavity ofthe"thorax"*after opening theheart,the interior ofthe heartand branchial artery,and the youngfishintheovary(ofa dog-

fish).

When

theheartwaslargeenoughtoadmitthebulbofthether- mometer,the greatest differences between thetemperaturesofthefish

andofthesurrounding waterwerefoundinthatlocality.

INSTRUMENTS.

The

thermometers usedintheseexperimentswere

made

expresslyfor thepurposebyMr.JohnTagliabue, ofNo. 66Fultonstreet,

New York

j

and haveprovedtobe verysatisfactory. Theyarefifteen innumber,viz

:

1.

Two

long thermometers, graduatedinfifthsofadegree,andcovering therange from 32°to100°F.,foruseasstandards.

2.

A

setoffiveshortthermometers, graduated infifths,marking10°

each,andcoveringalltogethertherangefrom 40°to90°F.

3.

A

secondsetof six shortthermometers,similar tothoselastnamed, markingfrom7° to15°each,andcovering therangefrom 30°tolOO^F.

4.

A

shortthermometerwith theend carryingthebulb curvedupon

*Theterm "thorax"isusedforconTenience' sake, as indicating the anterior part of thebodycavity,intheneighborhoodofthe heart.

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itself likeacrook,graduated infifths and marking from 55°to74PF.

(self-registering).

5.

A

Negretti-Zambra deep-sea thermometer, graduated ⁱⁿ degrees only,andrangingfrom about 25°to100°F.

Allofthese exceptingthe Negretti-Zambra aregraduated uponthe stems. Thethreehighestinrange oflot2,oneof thelongstandards, andthe crookedinstrumentwere

made

at ^firstself-registering, on the principle ofclinical thermometers,by a break ⁱⁿthe columnof mer- cury. Theyweresoordered in the hope thatit would bepossible to

make

someoftheexperimentsuponlivingfishintankswherethewater could be artificially

warmed

above thetemperature oftheair. Such experiments notbeing possible (for reasons

known

to you) theself- registration was destroyed by reuniting the broken mercurycolumn, and the necessary smallcorrection applied. The curved thermometer wasintendedforuse inaliving^fish, thebulbtobe inserted either into therectumor intoanincisioninthemusculartissue,andthestemtobe securedtothebodyofthefish,wbichwasthentoswim^{free in}thewater.

Thehighest temperature reachedwouldberegisteredbythethermom-

eter. This instrument,hketheotherselfregisteringthermometersoper- atingonthesameprinciple,can only be

made

available

when

the tem- peratureofthewaterisabovethat of theair,audthere has, therefore, as yetbeennoopportunityto

make

useofit.

Owing

to the curious molecular change which occursin theglassof whichthermometersaremade,whereby,afterfromsixmonthstoayear, the instrumentsshow anerrorofexcess offromhalfadegreetoadegree, thesethermometers,which werenecessarily"pointed"assoonasmade, arenotstrictlyaccurate. Theyshould be returned^to the maker and rated againbefore being used nextsummer, so thatthe necessarycor- rection

may

beapplied. Forthe time beiugthe errorhas been^tosome extent met byMr. Tagliabue,

who

has ^"overpointed"the scale about halfadegree. Iwouldalsosuggest thepropriety, incaseyouconclude tocontinuetemi^erature-observations, oforderinginadvanceoneortwo longthermometers,markingfrom 30°to 100°F., tobe"pointed"after sixmonthsand used asabsolute standards. Since,however,in these observations,absolute temperatureislessimportant thanrelativeaccu- racy,I have taken

much

pains to rate all the instruments together, comparing themwith the standard,andapplying such corrections as willreduce ^all the readings to its scale.

The

same error, ifany,will then be presentin all observations,and relative accuracywillbepre- served. InTableA, whichcontainsthecorrectionsdeducedfrommore thanthreehundredseparate comparisons takenatnearly every degree onthescale,thesmall thermometers in dailyusearenumberedfrom1 to 5 for thefirstset,andfromG to 12 for the secondset(which hasnot yet beenused),No.1beingthethermometeroflowestscale. Thecom- parisonswere

made

by immersingthe thermometers^{in water,}artificially cooledor heated. Onlythemeans ofeach 10°are given in thetable.

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No.1ofthe small thermometers and Negretti

&

Zambra's Nos. 43230 (between70°aud80°),38982, 40007, 42CGG,and43227 (between 70°and

90°),arethe onlyonestowhichit isworth while to apply acorrection in pra(*tice. Theotherdifferences,being less than half adegree,

may

be disregardedasnotlikelytoexceed the ordinaryerrors of observation.

TableA.

—

Thermometercorrections.

Thermometer.

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4. The Negretti-Zambra deep-sea tliermometers, which depend for their self-registrationupon the breakingofthe mercurial columnata certain place

when

theinstrumentisoverset in pullingitup,havesome- timesatrickofbreakingthecolumninthewrongplace,andsogiving afalse indication. InoneinstanceInoticedthatthebreakwasdiago- nal,instead ofbeingdirectlyhorizontal, as it should havebeen. Pro- fessorHind,of Halifax,informs

me

thathe hasnoticedthesamedefect andhasbrought it to the notice of themakers,

who

haveassured

him

thatithasbeencorrected in their morerecentformofinstrument. It should also be always remembered that the temperature recordedby these instruments is not that ofthe bottom, but ofabout a fathom above^it,owing to the playofline required in attachingthem to the sounding-line so thatthey

may

overset easilyand not strikeagainst thelead.

MODE

OF OBSERVATION.

The

circumstances ofthe summer'swork are too well

known

toyou to require repetition here. In explanation of the

smaU number

of observations(ninety-sevenforthewholesummer)itwillbesufficientto refer tothe unusual inclemencyoftheseason,permitting notmore than an averageoftwoexcursions aweek; and to the remarkable scarcity offish,which

made

alarge proportion ofthe excursionsblank as to results.

Many

^fisheswerebrouglitupinthetrawl-netoftheSpeedwell (thenavalsteamerusedbythe FishCommission),buthadbeensolong inthenet,presseduponbyeachothers'weight,as tocome upforthemost part dead; and always showing by their rectum temperature (which shouldbe nearthatof thebottom)thattheywere not in theirnormal condition as toanimalheat. Suchobservationsaswere taken from these specimens areenteredinthe table(B),butarcnot trustworthyforthe purposes ofthis investigation.

On

one occasionIsetatrawl-linefur- nished with some four hundred hooks,and took it in as soon as set.

Althoughnotmorethantwenty minuteshadelapsedbetweensettingand hauling,however,mostofthefishestakenwerealreadydrowned,andall

had lostalarge proportion of their animal heat. Since, therefore,no tanksof sufiicient sizeforkeeping fishes aliveunder observationwere available,thereremainedonlylinefishing,whichwascarriedonduring thelatterpartofthe

summer

as activelyastheweatherwouldpermit, fromtheyachtPhantom,belongingtotheEngineerCorpsoftheUnited StatesArmy, andlent totlieFish Comuiissionforthesuuimer. Thefish

werealltakeninCape

Cod

Bay,andwitliinten miles ofProvincetown, thetwo favorite localities beingthe steep edge ofa shoal

known

as

"Shank-Painter Bar,"between

Wood End

and PacePointlights,and a ledgein15fathomsofwatersomesevenmilessouthwestof

Wood End

light.

The rectum temperatures indicate,and Ihave no reason to doubt, that afishcaugiitwith alineandhauledrapidlyfromthebottomtothe

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vessel'sdeck has notbad time to materiallychange its temperature.

The

rectumusuallyshowedfrom half a degree toa degree above the temperature nearthebottomas indicatedbya deep-sea thermometer.

Havingarrivedontheground andanchored, thefirstproceedingwas tosound and take the temperatureof the water near the bottomby meansofa Negretti-Zambrathermometerattachedtothesounding-line, abouthalf afathom abovethe lead. The temperaturesof the surface waterandoftheairwere then taken with thesamethermometer, and, wherethedepth exceeded 20 fathoms, another observationwas

made

at 15fathomsforsubsequent comparison.

As

soonasafishhadbeen taken

itwasseizedand held firmlybyan assistant, his right hand grasping the throatunderthegill-coversandhisleftholdiug thenarrowest part ofthetail,whileIpasseda thermometerintotherectum andobserved the temperatureofthat part. Ithencut thefishopenfromtheisthmus between the gills toward the belly,exposing the heart,through the walls of which thethermometer was passedinto the branchialartery and the temperature taken agaiu. In this last manoeuvre the heart should not befieldbetween the finger and

thumb

ofthelefthand any longer than necessarytopassthethermometer-bulbintothe artery,lest heatbe communicatedfromthehandthrough thewalls oftheheartand givetoohigha reading. Thenfollowedobservationsuponthetempera- ture of the muscular tissue or other parts,

when

such were taken.

When

thefishwastoo small toadmitthebulboftheinstrumentwithin the heart aneffortwas

made

totakethetemperatureofthe bloodasit

flowed from ^it,or thetemperature of the liverwas taken,or,invery smallfishes,thethermometer waspassedintothe stomach, through the oesophagus.

The aboveprocedureis thatfinallyadopted,after refiectionuponthe unsatisfactory results following observations

made

ⁱⁿthe ordinary

way

(in the rectum).

As

tothe cruelty of the operation,I

am

inclined to believethatitismoreapparent thanreal,thefishshowing noconscious- nessof pain,bystruggling, i&c, afterthefirstincision.

BESULTS.

This summer's work must be considered to be, asIhave said,only experimental. Thesubjecthadtobestudiedfrom the beginning, withno recordsofprevioussimilarexperimentstogoby,and

many

observations werewastedin learning

how

to proceed.

Enough

has beenascertained, I think, toshowthatfishesdo develop animal heat bytheir

own

vital processesinthesame manneras,buttoalessdegreethan,otherverte- brateanimals. Inotherwords,itappearsfromthese experimentsthat

when

proper precautionshavebeen observedinmakingthe experiments allliving freshly-caughtfishes willbe foundtomanifestabodytemper- aturedifferingconsiderably fromthat ofthe waterinwhichtheyswim_; the degreeof differencevarying withthe perfection ofthe organization of thefish(andhence theactivity ofits nutrition),and^viththetemper-

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atnreofthewateriuwhichitswims. Thus the dogfish {Squalus acan- thias,LinuiEus)possessing afar moreperfect digestive and circuhitory system thanthe cod,showsa

much

greaterexcessofbloodtemperature abovethat ofthe surroundingwater;andcod takenatthedepthof15 fathomsinwater at 52°F.,showalessexcessthanothers takenin25 fathomsat 41°,buta greater excessthanblue-fish{Pomatonmssaltatrix (Linn.)Gill)takenatthe surface, at69°and70°,whichis presumably nearerthenormaltemi)eratureofthelast

named

fish.

Upon

thisquestionofnormal temperature,

my

observationshavenot thrown

much

light,oAving tothefactthatnearlyallthefishesobserved have come from water at about thesametemperature,andthat blue- fish,from which the most valuable results were to be expected on account of their activity and the

warmth

of the water which they inhabit,couldnot be taken with alineafterthetwodaysof theirfirst

appearance. Itisreasonabletosuppose,fromthe fact thatthecod, for instance,showsalessdifference

when

taken from warmer than from^

cold water,thatapointwouldsoonbe reached at which the temperature ofthebloodofthefishwouldcoincidewiththat ofthesurrounding water,andthat thispointwouldbe nearthe "normal"forthat family, or inotherwordsthelimitabove whichitcouldnotlive.*

The experiments are set forth atlengthinTable B, butsomeofthe conclusions for which they furnish a reasonable basis

may

be con- veniently stated here,consideringeachspecies separately.

1.

Cod

{GaditsmorrJma,Jjiiniiens). Twelveobservations. Thefishes

were taken with a hand-line, either at the edge of "Shank-Painter Bar," asand-bank about halfa milewidewhich makes outalong the end ofCape Codfrom Eace Point to

Wood End

light-house, in22-25 fathoms of water, oron the ^"Ledge," asmallrockyshoal lyingabout seven miles

WSW.

from

Wood End

light,where there arefrom13 to 15 fathoms of water,according to the state ofthetide. The rectum showed anaverageexcess of 0.97°abovethetemperature ofthewater near the bottom. In the bloody fluid resulting from the mixture of water with theblood escapingfrom the heart into the "thorax," the averageexcess oftemperaturewas3°,andintheheartitself 4.63°. In one instance an incision was

made

into the side ofaverylarge cod, fromwhicharterialbloodgushed forth.

A

thermometer i)lunged into thisincisionshowedonly1.5° excessoverthetemperatureofthewater nearthebottom. Itwasthisobservationwhichsuggested thethought thatthevenous bloodmightbewarmerthan thearterial.

* Prof.G. Bro-vvneGoode, wliohas beeninvestigating the question of the temperatures prefenertbyiliflerentfishes,conchides that the codanditscongeners seekwater at 38° to 42° F.;thatthetemperature range ofmenhadenliesbetween50°and75°

;

thatblue-fishare rarely tobefoundinAvaterbelow40°,ormackerelbelow45°;while black bass (Micropierus) thriveinthewaterofthenorthernlakes,frozen overfor threemonthsintheyearand neverrisingabove^65°.aswell asinthat ofthe Florida rivers,which becomesaswarmas 90°insummer. Differentfamilies,asthus appears, showverydifferentpowersofadaptationtoextremes of temperature.

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2.

Haddock

{Melanogramrmisceglefinis (Linn.), Gill). Eightobserva- tions. The rectum showed anaverageexcess of 1.3°over the temperature ofthe water near the bottom,andthecirculationan average of 5.3°.

One

fish, after ten minutes spent in a tub of water at 64.2°,

showed anincrease oftemperatureintherectumof7°. Another,which hadbeentiedbythetailandallowedtoswim15minutesatthesurface (at 69.5°)showed anincrease(intherectum)of1(5.8°; still11.5° below the temi)erature of the water.

On

the 6th September,fishingon the

"Ledge," the temperatureof thewater nearthebottomat15iftithoms was51.5°,whilethe recta ofthefirsttwoorthreefishescaughtshowed as lowatemperatureas 45°. Those caught later,after fishing in the 8ameplaceforanhourormore,showedarectumtemperatureof 51°. I suppose thattheindividualsfirsttaken(the tidehavingjustturnedto flood)came up ontheledgefrom deeperwater,theledgebeingofsmall extent,and showedthelowtemperature ofthewater fromwhichthey

had

come, gradually approximatingthat oftheshallower waterasthey remained longerinit. Thesefirsttemperaturesareleftoutoftheaccount in determining theaboveaverages, asuntrustworthy,owingtotheun- certainty ofthe temperatureofthe waterby whichtheyhadbeensur- rounded.

Haddock

were spawning as early as thefirstobservations (July30),whichfact

may

accountfor their somewhat higher tempera- turesthan thoseofcodtakenatthesametime.

3.

Pollack

{Pollachiuscarbonarius (Lmw.),Bonaparte). Asinglefull-

grownspecimen, weighing about25pouuds,wastaken on the"Ledge"

in 15 fathoms. The rectum temperature was 2.4° above that ofthe water nearthe bottom(42°), and that of thefluid in the thoraxafter opening theheart,4.5°. Severaloftheyouugofthisspecieswere taken from the wharves of Prcvincetown at different times and examined.

Sevenspecimens taken fromadepthof 8 feet(temperatureofwater60°),

and measuringabout8 inchesinlength,showed anexcess of 0.5° inthe rectum, 0.6° in thestomach(passing thethermometer through thegullet), and3.12°bythethermometer in themass ofintestines, &c.,next theliver. They were ⁱⁿ

company

with "tinker mackerel" {Scomber BeMyi,Storer), ofaspecies not observedin this harborformorethan thirty years.

4.

Hake

{Phycis chuss (Walb.),Gill). This fish was often taken ^at the same time with cod and haddock. Specimens were frequently broughtup,dead,inthetrawl-net. Thosetaken with a^linewereoften toosmallfortrustworthy experiment, but a verylarge individual,weighing over 35 pounds, takenAugust11,in25 fathoms of water, at 42°, furnished themostsatisfactoryobser\ation oftheseason,owingtothe largesize of the heartandthesluggishness of the fish,which

made

it

much

easierthan usualtobesure ofthereadings. Inthisinstancethe difference intemperature of thewater nearthebottom andthat ofthe rectum was 2.4°, and between the bottom water and the heart,9.8°.

Therewas anulceratedpatch about 2 inches squareontheside ofthe

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head. Couldthis liavebeen the cause ofthe unusuallyhigh temperature? Thepresence ofspawninthe

abdomen

protectedtherectumto someextent,nodoubt,fromthe chilling- effect ofthewater. Another specimen takenⁱⁿ15fathomsonthe ^"Ledge" gave a difference of^{3^*}

betweenthetemperaturesoftherectumandheart,thebottomtempera- turebeing uncertainforreasonsalreadystated. (Seepage313.)

5. Blue-fish {PomatomussaltatrLv {Linn.), Gill). Thesewere caught ononlytwooccasions,although often fished for unsuccessfully. Four specimensonthefirstday andoneonthesecondweretakenbytrolling,

andbroughtinafter\iolent resistance.

The

averagerectum temperature of thefirst four was ^0.25ohigher, and thetemperature obtained

by

an incision into the muscles of the side 1.55° lotver than that of the surfacewater fromwhichthefishcame(73.2°). Thesurfacewater was unusually

warm

on this occasion,and the fishes

may

havecome froma deeperandcolderstratum. Otherwise theindicationwould ap- peartobethat they resistedinsome

way

thehigher temperature than that towhichtheywere accustomed. TheyAvere taken from different schoolsand at different times.

The

single fish takenon thefollowing day showedarectumtemperatureof0.5°,andinthemusclesoftheside 1.7° above that ofthesurfacewater(70.5°). Themusclesofthesideof thislastfish,however,wereonly0.5°warmerthan the average(71.5°) ofthefourtaken thedaybefore.

At

thistimeIhad not yet begunto observethetemperatureofthe bloodⁱⁿtheheartandbranchialartery.

Young

blue-fish,3or4incheslong,havebeen caught fromthewharves at different times,buthavebeen too smallto affordtrustworthyobser- vations.

6.

"Tinker mackerel"

(young of iSeomher.scomber, Linnteus,and Scomber Dekayi, Storer).

No

fully-grown mackerel have been taken with thelineinthe neighborhood ofProvincetown for several years.

The

"tinkers," however,from to 8 inches long, abounded towardthe last ofthe season,and upon these severalobservationswere

made

at different times,the temperature ofthesurroundingwater being taken at6feetbelowthe surface,the lengthof linerequired in fishing. The anuswastoosmalltoadmitthebulbof

my

thermometers,andtempera- tureswerethereforetakeninthestomachthroughthegullet,andinthe immediate neighborhood oftheliver after dividing the larger blood- vessels. The averageoftwelve observations gives an excess oftem- peratureoverthat ofthe surrounding waterof 4.1°in thestomach,and 5.25° in the neighborhood ofthe liver. The individual temperatures weresurprisinglyuniform. ThreespecimensofyoungScomberDeJcayij taken from the wharf in 8 feet ofwater at (>0°, showedan average excessof 2,3° inthe neighborhoodoftheliver.

7.

Chogset

{Tautogalabrus adspersus (Walb.), Gill).

Two

observa- tionswere

made

uponasinglesmallspecimeninanaquarium-tank, the water being at 65.9°,and the thermometer passed into the stomach through thegullet.

The

excess oftemperature over thatofthewater was1.2°.

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8. ScuLPiN {CoUus octodecimspinosus, Mitchill).

A

single specimen showed anexcessin therectumof0.8°,andin theneighborhoodofthe liverof 3.2°overthe temi)erature of thesurroundingwater.

9.

Sea-raven

{Hemitripterus americanus (Gmel.), Storer).

A

speci-

men

kept^aliveina tubon boardofthe Speedwellfor three-quarters of anhour(thewatermarking^70.Go)showedanexcess inthe temperature ofits circulation over that ofthe water of4.4°. Another specimen brought up in the beam-trawl-net showed an excessin therectum of 17.7°andintheheartof 18.9°over thetemperatureofthebottomwater, buthadbeenhalfanhourinthetrawl,pressedcloselyon everyside

by

amassoffishes and sponges. Sothattheobservationisvalueless ex- cepting in that it showsthatevenunder abnormalconditions, solong as thefish lives,thereisadifference between the temperature ofthe rectum andofthevenousblood.

10.

GoosEFiSH

(LopMuspiscatorius,Linnsens). Thisfishisadmirably constructed for temperature experiments, being provided with a very largeheartandbranchialartery,and,moreover, with a highly organized digestivesystem. Unfortunately the onlytwospecimens observedwere brought up in thetrawl-netwith theabove-namedsea-raven,and

had

theirbodytemperatures abnormallyraised inthesamemanner. The^dif- ferenceintemperaturebetweenthe rectumandthecu"culationwas4.4°.

,

11.

Eel-pout

[Zoarces anguillaris (Peck), Storer).

Two

specimens taken in the trawl-net at the sametimeand underthe samecircum- stances astheprecedingshowedadifference betweenthe temperatures of the rectam andthecirculationofonly0.5°,thefishesbeing almost dead.

A

single specimen taken afterwards with thehand-lineshowed an excess in therectumof3°,andintheneighborhoodoftheliverof C°,overthat of thesurroundingwater.

12.

Flounder

{Hippoglossoides platessoides (Fabricius),GiU). In asin- glespecimentakenonatrawl-linethetemperatureofthecirculationwas 3°abovethat ofthe water near the bottom.

13. DociPiSH [Squahis acantJiias,Linnaeus). This species was

much

the most abundantofanynear Provincetown.

Owing

tothe highor- ganization of the digestivesystemoftheordertowhichthis fishbelongs, itwasto beexpectedthat theheatresultingfromthe processes of nutrition wouldbe foundin it to behighest. Accordingly,as the table shows,the differencesbetweenthebodytemperaturesandthoseofthe surrounding waterareheregreaterthan tbose manifestedbyotherfishes.

In aseriesoffivetakenfromcoldwater(40.4°)theaveragerectumtem- peraturewas4.4°andthatofthecircidatiou12°abovethat ofthewater nearthebottom. Thegreatest differenceoccurredina female, the ova- riesofwhich contained well-developed young,inwhichcase thecircu- lationwas10.0°warmer thanthesurroundingwater.

A

youngdogfish about 9 inches long,with umbilical vesicle still attached,taken from thisspecimen,gave anexcess of 20.0° inthe heartabovethe temperature of the water,the greatest differenceobserved during the summer. In this youngfish therewasofcourseno cooling of the blood during its

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passagethroiiglithegills(those organs nothavingyetcomeinto use), nor otherwise than mediately through contact with the body of its

mother. Anotheradultfemale withyounginherovisacshowed anexcess of 9.4P in therectum(oviduct!)and15.6°inthe heartoverthetem- peratureofthewater. In anotherseriesoffourteenobservationsupon specimens taken with atrawl-line, and halfdrowned

when

drawn up, thebodytemperatureshad approximatedthat ofthesurroundingwater.

Inthisobservation,too,theNegretti-Zambrathermometerfailedtoact, thecolumnbreakinginthewrongj^lace,sothat thetemperatureofthe bottomwaterhadto be guessedat from thatofthe recta of thefishes

andfrom previous observationsinthesameneighborhood. Itwasprob- ablynot higher than ^{4:2'^.}

Above

this supposed bottom temperature thefourteenhalf-drowneddogfishgavean excessof 2.2°inthe rectum andof 4.8° in theheart and"thorax." The greatest excesswas 0.7°.

Stillanotherseriesofseven taken with a^lineonthe"Ledge,"

when

the indicatedbottomtemperature could notbereliedon, forreasonsalready given(see p. 313),showedan averagedifferencebetweentherectumand hearttemperaturesof6.7°,whileinanotherspecimenthe difference be- tweentherectumandmuscleswasonlyl.G°.

14.

Skate

{RaiaeriuaceaandR. Iwvis, Mitchill). Three individuals of the former species,which hadbeenhalf an hour with a

number

of other fish in the trawl-net,andweretherefore uselessfor comparison withthebottomwater,showed anexcess inthetemperatureoftheblood overthat of therectumof3.1°. Fourindividuals ofthe latter species {R.Icevis)takenonthe"Ledge,"

when

thetemperatureofthe water from whichthefishcame was unknown, gaveadifferencebetweenrectumand circulation of2.9°.

SUMMARY.

Throwingout doubtfulandimperfectobservations,theresults ofthose experimentsinwhichthecircumstances weremostfavorable to accuracy,

may

be

summed

upas follows

:

Fisli.

(12)

STATES

First. Allfishesdevelopeanimalheat,itsquantity varyingaccording totheorganization ratherthan thehabits ofthefamily.

Second. This heatresultsfrom the processes of nutrition (chemical) andfrom the conversionofmuscular motion(mechanical). Thatresult- ing fromtheoxidationofthebloodislost inthegills; hence the venous bloodisdecidedlywarmerthanthearterial.

, Third. Spawning andbreedingfishes developemoreheatthan those not carrying onthese processes.

Fourth. Elasmobranchsand, generally,fishes with a highlydifferen- tiated digestiveapparatus develope more heat than those ofsimpler organization,and (probably)veryactive surface^fishes morethanslug- gishbottomfishes.

Fifth. Theintestinalcanalandarterialblooddonotcorrectlyindicate theanimal heatoffishes.

Sixth. The question of"normalrange oftemperature" remainsun- answered.

SUGGESTIONS.

Shouklyouthink it desirable tocontinue this investigationIwould suggestthattheinquiry include the followingdetails,indicatedby^last summer's experiments

:

First. Therange oftemperaturethroughwhich livingfishes

may

be carried. This might be observed by subjecting different species in tankstovarying temperatures producedbyiceorsteam introducedinto thewater,andnoting thebodytemperature of thefish

when

itbegins toshowsigns of distress. Each experimentwould expend afish,but the importanceandpracticalbearingofthisquestionof "normalrange"

of temperaturemightjustifythe expense.

Much

couldbe learnedby observingthetemperatureofthewateratwhichthefishbeginstoshow signs ofdistress. In such aharborasthat ofProviucetowu aconsider- able difference in the temperatureofthewater can be gotbytowinga wooden-latticed tankinto shallowwater at ebb-tide andintosuitable positions atflood-tide.

Second.

Amount

ofoxygenrequiredbydifferentfishes. This

may

be approximatedbykeepingdifferentspeciesunderobservationinseparate tanks without afresh supplyof water.

Third. Lengthoflifeafterbeingwithdrawnfromthe water, andsub- sequent durationofmuscularirritability. Also the

number

of respira- tionsperminuteindifferent species

when

atrest.

Fourth. Influence ofmuscularmovements ontemperature. This

may

be observed bytying a fish bythe tail,inthewater, untilitexhausts itselfbystruggling,and then taking the temperature,tobecompared withanobservationuponanotherindividual ofthesamespeciesunder similarcircumstances,butatrest.

Fifth. Comparative activityof nutrition as indicatedbythepercent- ageofnitrogenousmatterinthe excreta.

Sixth. The repetition of similar observations on the plan of those

made

lastsummer.

(13)

318 PEOCEEDINGS OF UNITED

STATES

NATIONAL MUSEUM.

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(14)

PKOCEEDINGS OF UNITED

STATES

l-gog

(15)

320 PEOCEEDINGS OF UNITED

STATES

NATIONAL MUSEUM.

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(16)

PROCEEDINGS

OF

UNITED

STATES

PREVIOUS INVESTIGATIONS.

Dr.John Davy,iiia paper read beforetlieRoyalSociety, in 1885,on thetempeiatiu'e ofsomefishes alliedtothemackerel,observed that the bonitohadatemperatureof 90°F.

when

thesiUTounding

medium

was 80.5°; and that it therefore constitutedanexceptiontothegenerally- received rule thatfishesareuuiversaUycold-blooded.

*Tarrellsays:

"The

consumptionofoxygen,however,issmall; and thetemperatureofthebodyoffishes that swim near thebottom,and are

known

to possess but alowdegree of respiration,is seldommore thantwoorthreedegreeshigher than the temi)erature ofthe waterat itssurface." Thisstatement does notappeartobe foundeduponactual observation, sincethetemperature ofa bottom-feedingfishtakenfrom wateratanyconsiderabledepth might be,andusuallyis,

much

below that of the surface water, andstill considerablyabove the temperature of thewater inhabitedbythefish. Thus,inthewatersabout Province- town, thediftereneebetweenthebottomandsurfacewatertemi>eratures at20 fathomsisfrequently asgreatas30^_F.

At

thetimeof Yarrell's writingbut^littlewas

known

ofthetemperature<»fthewaterat consid- erabledepths, the deep-sea thermometer being an instrumentofcom- paratively recent use. The quotation illustrates sufficiently well the mistaken theorywhichunderlies the universal beliefinthecold-blood- ednessoffishes,and which looks to the consumption of oxygen only forthesource ofanimalheat.

As

has already been shown, whatever heatisdevelopedbythisprocess infishesis quitelosttoitsbodytem- peraturebythecontactofwater with the aerated bloodinthegills.

Theattention ofthisexcellentobserver(Yarrell)wasstronglyattracted tothequestionoftheanimal heatoffishes,andhe hascollectedalarge

number

ofquotations bearing uponthe adaptivepowerof fishesto ex- tremesofheatandcold,whichwillbereferred to later on.

He

attached agreat deal ofimportancetothecorrelationofmuscularirritabilityand

"quantityof respiration" in this connection,npon which subject he says:t " Physiologists have shownthatthe quantityof respirationis inversely asthe degreeof muscular irritability. It

may

be considered asalawthat thosefishwhich swim near thesurface ofthewaterhave ahigher standard of respiration,a low degreeof muscularirritability, greatnecessity for oxygen,die soon, almost immediately

when

taken outofthe water,and havelieshpronetorapid decomposition. Mackerel, salmon,trout,andberring are exaaiples.

On

the contrary those fish

whichlivenearthebottomofthewaterhavealowstanihird of respiration,a high degree ofmuscularirritabilityand lessnecessity for oxy- gen5 theysustainlife longaftertheyare taken outof the water,and thenfleshremainsgoodforseveral days. Oarp,(codI),tench,eels,the diflerent sorts of skate,andalltheflatfish

may

bequoted."

As

against

*History of British Fishes. London,JohnVanVorst,I84I. Introduction,p.xx.

tYarrell,oj).cit. pp.xvandxvi.

Proc.ISTat. Mus.79 21 IVIarcll

25,

1

880.

(17)

322 PROCEEDINGS

OF

UNITED

STATES^~

NATIONAL MUSEUM.

theabove statemeut respectiug the speedy deathof surfaceswimmersis thefactobservedbymyself, thatabhie-fish[Pomatomiissaltatrix(Linn.) Gill),takenAugust5,showeddistinctsi<?nsoflifeafterfifteenminutes spentuponthedeckof the yacht,andthat afragmentcomprising- rather morethanhalftheheart continued to pulsate for eight minutes after being separatedfrom the body,andtorespondto artificialstimulusfor fifteenminuteslonger.

Prof.G.

Brown

Goode,oftheFishCommission, has beenengagedfor someyears in the investigation of the relations of our Atlanticfishes towater temperatures. Last year (1878)he

made

several direct experi- mentsupon bodytemperatures,testingthetemperatureof the rectum withathermometer and comparing itwiththat of thewater as indi- cated by a deep-sea (Miller-Casella) thermometer. The experiments were

made

uponcodand haddockforthemostpart,andthedifterences betweentherectum ofthefishand thewater from whichit had been taken were found to be inconsiderable, rarely exceeding one degree Fahrenheit,aswasthe case in the similarexperiments

made

bymyself lastsummer. In the cursory examination which 1 have

made

ofthe literatureof thesubjectIhavefoundnoother records ofexactexperi- mentsupontheanimal heatoffishes.

There seemstobe,however,nolack of authority for thegeneralbelief that theseanimalsare cold-blooded,inthesense thatthey take onthetem- peratureof the

medium

whichsurrounds them, and havenot,likethe highervertebrates,alimitednormal rangeoftemperature,bejond which

life cannot be longsustained. Professor

Owen

lendsthe weightof his great

name

to thisopinion (in hisgeneral division of vertebrates into Saem(tfotherm((andHaematocrya),andthe instanceswhichI

now

quote oftheendurancebyfishesofextremesofheatandcoldwithoutapi)arent injury aresufiicientto establishincontestably thefactthattheydopossess such endurancetoaremarkabledegree. The^earliercitations aretaken atsecond-handfromYarrell(Introduction toHistoryof British Fishes).

*Mr.Jesse{Gleaningtiin N'afuralHisfori/^2dseries, p.277^tells ofa friend

who

saw a goldfishwhich had been frozen into a blockofice,

andafterwardsthawedintolife.

*Dr.Richardsonrelatesthat the gray sucking carp,

common

in the furcountries of.Vrctic America,

may

befrozenand thawed out again withoutinjury. {Fauna BorealiAmencana,vol. 3.)

Perch

ha\-ebeenfrozenandtransported for miles,returning tolife

when

thawed (T. S. Buchawan, Tntroduction to the Study of ^Nature)', and John Hunter says {Animal Economy): " that these (fishes) after beingfrozenstilli-etainso

much

oflifeas

when

thaw^ed toresumetheir vitalactions,isafact so well attested that

we

areboundto believeit."

tMr.J.

W.

Milner(AssistantFish Commissioner),hada

mud minnow

'Quoted byYarrcU,loc.cii.

+Goode OntheMigration ofFishes. ReadbeforetheAmericanFish Cultural Associa- tion,February28, 1878.

(18)

pkocp:i:dings of

united

states

national museum. 323

(Umbralimi [Kirt.] Griiuther) wliicliwas frozen within solid ice iuan aquarium-globe,three orfour times,andeach time regaineditsvitality

upon being-thawedout. Instancessimilar to theforegoing can bead- ducedindefinitely.

*The only hyherimUoit which is definitely know^u to occur

among

fishes,says ProfessorGoode, takesplace iu the freshwater lakes and streamsof cold regions. Thefishesaredrivenby cold intothedeeper waters, andthereremaininastateof torpor, proportional iudegreeto theamountof cold which they experience. Hybernation does notap- pear to be in any casea voluntary act. The fishes do not become torpid of their

own

accord. They avoid it as long astheycan,and onlysuccumbwhentheyare deprived ofthe means of escape. They neverbecometorpidwhenthere are greater depthstowhich they can retreat.

tDr. C. C. Abbott reports of the fresh-water mullet {Myxostoma ohlongum): "ISTodegreeof cold seems to affect themovementsof this si)ecies,and hundreds can frequentlybe seen under the ice, moving slowly along the bed ofthestream,feedingupon thewiltedremnants of pond-lily and splatter-dock plants. ^* ^* ^* This applies also to our

common

roach {Stilbe americana),which,to a less extent,braves thechillingwatersofour streams throughout the winter, and,in con- sequence, sutfers from the persecutions ofthe three species ofpike {Esoxreticidatus,fasciatus,jwrosus) inhabitingourstreams."

ISeealsoIMr.KudolphHessel'sobservations upon the wintertorpor of the carp. This appearsto be atrue hybernation,during which,al-

though the fish takes no food in some climates from October until March,thereisnodiminutioninweight.

On

the other hand,fishes have been reportedas livingandthriving inwater at an exceedinglyhigh temperature; highenoughtoproduce deathbycoagulation of thealbumenintheirblood and tissues,unless thereissomei^rovisionby whichtheir interior parts aremaintainedat atemperature lowerthanthat of thesurroundingwater.

As

theexist- enceofanyprotection analogous to that afltbrded to

mammals

bythe function of perspirationandevaporation seemsobviously impossibleto animals living in thewater, it is difiQcult to understand inwhat

way

sucharedu(itionintemj^eraturecan bei^roducedandkeptup.

§Thus,

Humboldt

and Bonplandobserved livingfishes inhotwater thrownupfromavolcanoand showingatemperatureof210°F.

§Desfontainesfound a Ghromis in the hot springs of Cafsa, in

Bom-

bay,thewaterinwhich showed30°R. (97.5°F.),and

Shaw

afterwards sawsmallmullet and perch iu thesamesprings. {Travels inBombay,

folio, Oxon.1738,p. 231.)

*Goode,loc.cit.

tNoteson someFishes oftheDelawareRiver. UnitedStates FishCommissioner's Reportfor 1875-76, p. 825.

tThe Carp anditsCulture. FishCommissioner'sReportfor1875-76,p. 869.

§QuotedbyYarrell,loc.eit.

(19)

324 PROCEEDINGS

OF UNITED STATES NATIONAL

MUSEUM.

*Saus8uresaweels, rotifern, audinfusoria in hotsi)rinj;sof Aise, iu Saxony,in1790, atatemperatureof113°F.

*BrucesaysthatatFeriana, the ancient Thala, arespringsof

warm

water without the town,where he sawsmall fishes,4 inches long,not unlikegudgeons. The temperature is not noted,but hesays:

"Upon

tryingtheheatbythethermometerIremembertohavebeen

much

sur- prised thatthey couldhaveexisted,andeven not beenboiled,bycon- tinuing solongintheheatofthismedium."

*Facts mentionedby Somerset induced Broussounet to

make

some experimentsonthedegreeofheatwhichriverfisharecapableofendur

ing. Details of the degrees ofheat are notstated,but

many

species livedseveraldaysinwatertoohotforthehand. (Thisaudthepreced ingcitationfrom Dr.Hodgkin'sadditions to the translation ofDr.

W

F.Edwards'work

"On

the Influence ofPhysicalAgentsonLife.") tProfessorGoodewrites: "In

warm

countriesananalogous

phenom

enon (to hybernation) takes place, which has been called cvstivation

When

the lakes and streams are dried up bythe heat,the fish, seek refuge in the deepest pools, and

when

they too are dried,they bury themselvesinthe

mud

atthebottomandremain torpid untiltherainy seasonrefillsthe reservoirsandrevivesthem."

J

Day

reportsthatonJanuary18, 1869,hevisiteda largetankwhich was then almost dry, having only about four inches of waterin the center, while thecircumferencewas hardenoughtowalkon. Thesoil

wasathick and tenacious bluish clay, from which,fully thirty paces fromthewater and two feet belowthe surface,were takenfiveliving fishes.

Two

were Ophiocephahia punctatuH,andthreewereRhincohdella aculcata. Theywere covered witliathick adherent slime. "J.Z^ were livelyandnot in the leasttorpid.''^

Day

alsoreportsAmpJiipnouscuckia as having been dug up under similar circumstances. Mr. Whiting, chiefofficerof thewestern provinceof Ceylon,iuformed ^Sir

Emerson

Tennentthat he hadbeen twicepresent

when

the peasantshadbeen diggingupfish ofninetotwelve inches long, full-grown and healthy,

^\\\c\xjumpedonthe hanlcwlienexposedtothelight.

Batrachians,tortoises,andlaud-snailsarecommonlyfoundina torpid stateduringthehotanddry months,a statewhich

may

trulybecalled cvstiration, but which differs decidedly from the condition of activity described aboveasobservedⁱⁿburied fishes,andfi)rwhich thereisno very obvious explanation.

Theinstances cited aresufficient toshowthat thepopularbeliefthat fishes possess no animal heat of their

own

rests upon well-attested observations.

At

firstsightitisdifficult tounderstand otherwise

how

theseanimals can undergo the extremesofheat and coldwhich they have been

known

to undergo and continue to live. Yet,

when

the adaptability of birdsand mammals, whose normal rangeofbodytem- peratureissoextremelynarrowcomparedwiththat offishes,toextremes

*Quoted byYarrell,loc.cit. tGoode,ojj.cit.

t" Fresh WaterFishes of ludia,"p.28.

(20)

PR0CEEl)I\G8 OF UNITED STATES

ofheat and cold is fairly cousidered, the necessityfor this inference seems to l>c not so veryol)vions.

And

no one appears to liave tried theexperimentof subjecting- thesameiiidivirlualstogreat differences of temperature,whereby tlieimmenseeffectof inheritedadaptationwould Imve beenthrownoutoftheaccount.

With the exception of the often-quoted paragraph from Humboldt andBonpland,noneof theforegoing observationsattest a higher temperature than 1130F.,notedbySaussureasendured byeels inthehot s])ringsof Aise. Thisisbutlittle above the temperatureol>served at r\)rt

Yuma,

in California,which isoccupiedasamilitarypost.

Ihavenotyetfoundthe original passage. from which the statement credited toHumboldt andBonplaud,astolivingfishinwateratatem- ])erature of 210°Fahr.,is quoted. Yarrell gives no indication ofthe pi-ecise ])lace from which he cites. In an essay* ^^iSur toie nouvelle r.sjUTe(k pimelodm''^^{P. cijclopnm), however,

Humboldt

writes: "L'ha- sarda vouluqueces inondationsvoh;aniques n'eussentpaslieul'ann6e (|uej'aipassee dansles

Andes

de Quito; matslespoissonsvomis parles volcans sont un phenoinene ^si

comnmn

etsi generalement(*onnude tonsleshabitansdece pays,qu'ilne pent pas rester le moindre doute sursonauthenticite."

From

whichitappearsthat,onthe occasionre- ferred to atleast,hewasobliged to relyuj)on second-hand testimony

;

especiallyuponthat ofM.deLarrea, of Quito,

who

hadcollecteda cab- inetof minerals,was instructed inchemistry,andhad lookedinto the records of

many

villages aroundCotopaxi.

From

this gentleman he learnedthatin 1(391myriadsofthe fishes inquestionwerevomitedup fromthevolcanoof Imbabarri,causinga fever

among

the neighboring people.

Some

^Indians ^assuredhim("quelques Indiens m'ontassure_") thatthefisheswereliving astheycame

down

the side of themountain,

"mais cefait ne me paroit assezarcrc:'' Very few of the specimens that he sawwere suflScientlydisfigured, in hisopinion,to indicate ex- posuretoverygreat heat,andthespecimenscameoutofthemountain mixedwithanargillaceousmud.

Humboldt

conjecturesthe existence ofsubterraneanlakeswhencehe supposesthefishestohavecome. ]S"ot

having foundthe original passage,I cannot, of course, say

how

larits

contextmightmodifythe inferenceswhich havebeendrawnfromitas (pioted,butit isevidentthat at the time herereferredto,at least,he hadnoidea that thefisheswerealive

when

thrownoutfrom the moun-

tain,nordidhe

make

anyrecord of thetemperature(210° Fahr.)

named

inthecitation.

Theinstances of frozen fishes thawed into life again differ inkind ratherthanindegreefromfamiliar experienceswithfrozenfingers, toes,

andears restored to their integritybygradualthawing, irhoitheyhave not heen frozentoo lomj. Inno case, sofiir asIknow, has anyattempt been

made

to ascertain whether the frozen fish retains initsinterior parts a temperature above the freezing-point; nor is it stated that

*/?ecHfi7(Vobsvrfcitiomde zoologieet (Vaiiatomie comparee, Paris, 1811, tonic1'',]).22.

(21)

326 PROCEEDINGS

OF

UNITED

STATES

NATIONAL MUSEUM.

fislieshavebeenthawediutolifeafterhaving beenfrozen foranygreat lengthof time.

*Dr.Eichardson's remarksinarecentcommnnicationtoWature,upon

''Suspended Animation,"are pertinentto thisinquiry. "It ishardto saywhetherananimal,likeafish,frozenequallythroughallitsstructure, is actually deatl in the strict sense ofthe word, seeing thatifitbe equally and uniformlythawed it

may

recover from a perfect glacial state. In like manner it

may

be doubted whetherahealthy, warm- blooded animal suddenly and equally frozen through all its^•partsis dead,althoughitisnot recoverable,becausein the very act oftrying to restore itsome inequality in the direction is almost certain to de- termine afatal issue,owing to the transitionofsomevital centre into thepectousstate ofcolloidal matter. Ido not,consequently,seethat coldcan beofitselfandalone utilized for maintaining suspendedani- mationinthe largerwarm-bloodedanimalsoffullgrowth. * * * It isworthyofnote thatcoldisantiseptic, asthough whateversuspended living action,suspendedalsoby some necessity or correlative influence theprocess of putrefactive decay."

Kespectfullv submitted.

J. H.

KIDDER.

Hon.

Spencek

F.Baikd,

United StatesCommissioner of Fish andFisheries, Washington,I). C.

February

10. 1880.

DEStiRIPTlOIVS

OF NEW GENERA AND

MFEC'IE!!!

OF FISHES

FROIH

THE COAST OF

€AI>IFORNIA.

By W.

M.I.OCKI]\€iTO]>f.

1. Leiirynuis paucidens,j;<'n.ft sp.uov.

Generic

characters.

—

^Family^Zoarcidw,^alliedto Lycodes. Ventral finspresent,short; no teethonvomer and palatines; dorsaland anal finscontinued withoutinterruptionaroundthetail. Scales small,butevi- dent. The

name

^is from ^{Xeoiu,^}

—

smooth; ^N>vr?

—

vomer, in allusion to the characterwhichchieflydistinguishesthegenus fromLycodes.

Specificcharacters.

— Body

elongate,eel-like; extremityofsnout subtruncate; profile of remainderof snout and head conic, slightly convex over the eyes; highestpartofthe dorsal outline anddeepest part ofthefishperpendiculartoa,j^ointabout

midway

betweenthepos- teriorendofthelowerjaw and thebaseofthe pectoral;fromthispoint to the slightlyrounded endofthe caudal thebodytapers regularlyboth above and below.

Head

broad, the sides(viewed from above) almost straightfromtheopercula toabout half-waybetweentheeyeandthetip ofthesnout,thencerapidlyapproachingandmeetinginanobtusepoint.

Greatestdepthofbodyfromalittlemorethantentoalittlelessthan eleven times; lengthofhead

^—^

^timesⁱⁿ^the^total^length^; ^{snout 2||}

*Quoted fromForestandStream,September4,1879.