Individual Variation in the Skeletons of Birds, and other matters

>SS7-] Correspondence.

26c

Anthus

spragueii.

Four

seen.

Thryothorus ludovicianus.

One

seen.

Thryothorus bewickii.

One

seen.

Turdus

fuscescens.

One

seen.

Turdus

aonalaschkae pallasi.

Not common.

This isa prairiecountryand

many

of the birds

named

in Mr. Drew'slist arenotfound here.

—

^P.

M.

Tiiorne, Capt. 22d Inft'y, U. S. A.,Fort Lyon, Col.

CORRESPONDENCE.

[Correspondentsare requested towrite briefly and tothe point.

No

attention ivill bepaidtoanonymous co»i»iu>iications.~\

IndividualVariationintheSkeletonsofBirds,andother matters.

To the Editors of The Auk: —

Dear

Sirs:

—

-Beforesaying anything about the individual variation in the skeletons ofbirds, allow

me

topass afewremarks

upon

the lettersof Dr. Stejnegerand Mr. Lucas,which appeared in the last issueof 'The Auk' (April, 1SS7), and wherein I

am

called

upon

to hold up

my

hands for a

number

ofsins. Dr. Stejnegerisquite correct in calling

me

to ac- countforsayingthat'suchforms asPi'cus'werebirds witha'two-notched' sternum;all

Woodpeckers

have

four

notchesintheirsternums,as

we

well know, andI

must

be pardonedfor

making

sucha lafsuscalamior lapsus memories, whicheveritwas.

When

Dr. Stejneger asks thequestion,

how-

ever,with respecttothe Swifts and

Hummingbirds,

and says,

"What

in the nature of thesebirds' flighthasbrought about such an extraordinary similarity, osteologically, myologically, and pterylographically in the wing-structure of the Swiftsand

Hummingbirds,

as

compared

withthatof theSwallows?"

—

it'sanothermatter.

And

so far asthe osteology of the wing-structure ofaSwiftanda

Hummingbird

isconcerned andtheir"ex- traordinary similarity,"Iwould simplyinvite Dr. Stejneger's attentionto a shortpaperof

mine

in a recent issue (theApril number,1SS7,Ibelicve) ofthe 'Proceedings' of the Zoological Society of

London,

wherein Ihave figuredthehumerus for a Swallow, Swift and a

Hummingbird,

and ask

him

where the "extraordinary similarity"

comes

in, in that part of the wing-structure of thelasttwo forms mentioned?

As

tothe other extraordinary similarities I will dwell upon

them

in anotherconnection,later.

Mr. Lucas'sletterrequires

no

special notice, for I

must

still plead not guiltytothe chargeof havingpublished an "imperfect"drawing of the base of the skullof Tachycincta thalassina,andthat isthe sole point of

2

66

Correspondence. [Juty

issue in hiscommunication worthy of consideration.

To

those

who saw

Mr. Lucas's reproduction ofthe

handsome

woodcut the P. Z. S. gave

me

of

my

^{drawingof the structure} inquestion, nothing need be said. But tothose

who

have not yet hadthat pleasure permit

me

tosaya

word

in

my own

defence. Itwillbe

remembered

bythose

who

havereadthisdis- cussion, thatMr. Lucas claimedthat

my

^figure,justreferred tois "imper- fect" from the fact that the maxillo-palatincsare broken _off.

My

figure appeared in the P. Z.S. for1885 (Dec. 1, p. 899,^figF.), and Mr. Lucas's purported copyof it appeared in'Science' (No.223,p. 461,^fig. 1),

some

timeafter

my

original

memoir

appeared.

Now

itwas

my

intention,atfirst,topresenthere photographiccopiesof

my

drawing and Mr.Lucas'scopyofit, inordertoshow, whatI

am

afraid I

must

say,the unfair

manner

ⁱⁿwhich he has acted in the premises in ordertosupporthisviews.

Butspacein 'TheAuk'isfar too valuable in

my

estimation to further argue the point,

—

^{and I will only say that in the copy (?) which Mr.}

Lucas

made

andpublished of

my

^drawingthebackward-turnedends of the maxillo-palatines havebeen removed, which endsare

shown

in

my

origi- naldrawing, small thoughthey be.

With

this briefremark I close

my

case, and itwill notberesumed by

me

under any circumstances; no one

welcomes

honestcriticism

more

heartilythan thewriter,

—

butisthathon- est criticism?

Speaking

now

of the individual variation in the skeletonsof birds I

would like to reproduce here, in illustrationof it, a pairof skulls which figuredin anarticleof

mine

in 'Science'not longago.

As many

readers of the'The Auk,' both at

home

and abroad, possibly

may

not subscribe forthatestimable journal, Iwas^{led to}believe that in bringingthese draw- ings

more

directly before ornithologists,

many

^of

them

could not fail to findsomethingofinterest in them.

Theseeach representa skull

(X

2) ofthe Yellow-headed Blackbird (A*.

xanthocephalus)^, thespecimens having beencollected by myself,andare

now

in

my

possession.

We

are very wellaware that throughoutanimate nature,all specific formsvary

more

or less,and that thecorresponding structures ofanytwospeciesare neverquite alike,eitherin formorsize.

So

^faras birds areconcerned, I think itwoidd be hard to finda pairof skulls,thatwould bettershow, takingthispartoftheirorganizationinto consideration,

how

greatthisvariation

may

besometimes. It isveryevi- dentthatan exact,description ofoneof these skullswould notanswerfor the other, notwithstanding that they are both from birds of the same species,

—

^yetageneraldescription could be written^thatwoiddfullycover all their salient features, and sufficiently differentiate

them

from descrip- tionsofthe skullsofotherbirds.

With

respect tomeasurementsand exact descriptions, however,forany structure, forany particular speciesof bird,

we

arein the

same

quandary in our accounts of such structures

among

the lower vertebrates as the anthropotomists arewithrespect to descriptive

human

anatomy.

Much

might be writtenaboutthesetwoskulls here figuredwhich lackofspace forbids, butthis willnotdebarthe thoughtful ornithotomistfrom

making

i33₇.] Correspondence.

267

a careful study of

them

for himself.

One

thingit

must

point out toall,

and thatis, forourdescriptions ofsuch structures tobe broad andfull

we

should havebefore us,

whenever

it is possible,abundance of^material,

—

and,too, with respect to measurements,

we

should aim to establish re- liablestandardsthrough thecalculation of averages

computed

fromcare- fullytaken individual data.*

RIGHT

LATERAL VIEW OF THE

SKULLS OF ^\". XANTIIOCEPHALUS,

$

C?.(X2).

pp,parsplana; na

tnasal; mxp,maxillo-palatine; v,vomer; nix,maxillary;//,pal- atine;pt,pterygoid; ins, manibularsesamoid; q,quadrate.

* Since publishingthe above in'Science,'Mons.^Alfred Grandidier, Memb.del'ln- stitutedeParis, writes

me

fromParis thathe fullyagreeswith

me

inthemarkedvari- ation thatmaytake place in the skulls ofthesame species of birds,and invites

my

attention to figures\-id ofplate 156aof his^'Birds of Madagascar^'; and to figures 2and4of plate 18 of his ^'Mammaliaof Madagascar.' Iregret tosaythat thiswell-

knownworkisnot before

me

atthepresenttime.

20o

Correspondence. [July

At

the firstmeetingoftheA. O. U.

Committee

onthe Classification and Nomenclatureof North

American

BirdsI

was

honored by havingthe re- quest

made

of

me

by the

Committee

to

make

a report

upon

the en- tire structure of Chamoea fasciata with the view of throwing, if possi- ble,

some

light on its position in the system, and although that is severalyears ago, all

my

continuedeffortsfailed in securingthe necessary material to thecarrying out of sucha task. Recently,however, through thegreatgenerosity ofMr. G. Frean

Morcom,

ofChicago, andthetimely assistance ofMr. F. Stephens, ofSan Bernardino, Cal.,thanksto both,I

can

now

reportthatIhavein

my

possessionfortheaforesaid pieceofwork, anexceptionallyfineseriesof alcoholicspecimensoftheChanucafasciata.

During

the yearsofwaitingIhavenotbeenidlemyself,andIhavealcohol- icsof

many

desirableformstocomparewithoursubject,but^still man}'are

among my

desiderataand will beacknowledgedwith gratitude, aswell as dulysoin the

Memoir,

^ifsenttome.

Such

a bird asAccentor modularis*

would

come

into play,perhaps, or

some

ofthe Old

World

forms of the Timeliidse; anyspeciesofthegenus Lophophaneswill be acceptable, and

Wrens

andTits generally. Justassoonasother unfinished

work

will per- mit me,Iwill

now

putforth

my

bestendeavortorendera full accountof thestructureofthisinterestingspecies,and that willfall withinthe year,

—

thepowerspermitting.

Very

respectfullyandfaithfullyyours,

R.

W.

SlIUFELDT.

Fort Wingate,

N.

Mexico.

May

21, 1SS7.

'ScarcityofAdult Birds in

Autumn.'

To the Editors of the Auk

^:

—

Sirs: In a late (January)

number

of'TheAuk' Mr.

Beckham

asksfor an explanation ofthefactthatout of threehundred andsixty-seven birds collectedby

him

in Colorado andKentucky between Sept. 1 and Nov. 22, 1SS6,three hundredand forty-eightwere birds of the year,leavingonly nineteen adults, ofwhich eleven "werespeciesresident

where

collected."

The

question thusraised

was

anticipatedand answeredin

my

recentpaper onBirdMigration_fby the following:

" IV.

That

with

most

North

American

birds the majority of adults eitherprecede or

accompany

the first flights of

young

in theautumnal migration I

am

convinced by a long field experience, during which, moreover, Ihave failed tofindany proofthat the

young

ofasingle spe- ciesprecede the old.

My

evidencein supportofthis statement isoftwo kinds: (1) Observations

made

on thedeparture of birdsfromtheirbreed- ingstations. (2) Observations on flights arriving from localitiesnorth of the stationsof observations.

The

first class of evidence, in

my

opin-

* Professor Alfred Newton,F.R.S.,writes

me

from CambridgeUniversitythathe hashadcollected for

me

afull seriesofthis bird,forwhich

my

most sincere thanks are gratefullytendered.

tMem.

Nutt.Orn. Club,No.I,March,1886, pp. 15-16.