New-York tribune., 1874-08-18
ASCENDING PROCESS OF THE AsTRAGALUs
IN BIRDS.
pY PROF. EDWARD S. MORSE.


MIR. Morse first described the ascending pro-
cess of the astragaus in bi seen in the hen The
astragalus IN birds coOsses early with the end OF the
tbIa aud this process, has been called ascends as
spur from the upper side Of the asragalus in front OF
Tho ihia In certain extinct reptiles. like HypshOpho-
don IBlaps and others, the ascending process Oh the
astragaius shows itself as an avian character:
few wears ago Prof Wyman discovered that this
process indepeu dent center OF ossitcatlon ana
therefore could not be a process or the bOhe. Mr:
Morse had interpreted this bone the utermedlu OF
secenlaur The intermediums ,arsal bone. occupying
position between the astragalus aud calcaneuln In
The Sdurlns, turtles, aud oAerlepes tnls bone j. WI
seen u certain amphbians as in The saamanders, the
bone is long. dgeshaped, and partially projects be-
Mr. Morse has expressed his belief that the ascending
process OF The astagdus represented the lneTnedum
EewYork Lyceum Of Natural History theoretic hgure
Of he proper position OF TINS bone III brdS, c0mdrg
WIN the !nleTle OF certain etI5h'huels. ne
explained it, position IN front OF Che tDa as supposed
process OF the astragalus, by calling attention 10 the
excessive tendency 20 ancnYOSis IL BIRDS The widening
Of the tipa include ali tne ;arsals within lis width
ttia and as II early untes with the astragalus, has
naturally been mistaken.
gardg the OF this bone IN studying the embTyOs
of common Tern at Penikcse Island. la the embryo
hid he iutcrmedium showed as long oval bone the
astracaluS and clcaneum dSlug NJ between the uDd
and hOula seen in the lower reptiles.
In ths connection lt j. interesting 10 observe that In
the mammalia the intermedmm docs not occur, and
Egnbaur has expressed the opinion that the astrasus
OF mammals Teprcs ants the astragalus ana iuiermedum
united and these INVESTIGATIONS mleht possibly 70 10
confirm that opinion III the fact mat III reptiles the IN
ferneduin Is separate in birds II is separate IN the
Young BIRD but connected with the asrdgalus IN the
adult stdtc. while in mammals, II Stgeubadr Is Il-ht, II
L. always 80 connected
Pro. Gin and Eugene NJ. Hioard of Ann Arbor, Mich,
discussed Prof Morscs paper; Prof Gil SAID lie could
perfectly with Prof. Morse at least on the main
points IL had done great good to science 1t has be-
coming said he, and more evident as time has
uTpgrt ssed that the bridge connecting birds ana rep
ines s, being made very firm, ana now II l. very ap-
parent that between mammals ana birds VIC nave more
Of a gap than between birds and reptiles Now the
question is now plrds and reptiles might differ EX-
fsrnal appearances very deceptive indeed II Is
only ANATOMY that is really basis OF clasSlhcatl0ns
Between birds and mammals there are so great differ
enccs that mus; isolate mammals as distinct group
whIlo rap.ics and birds can he combined III another
group. might endmerate some 10 OI 70 characters OF
one / can scarcely mention more than Two or three
character, that distinguish birds from reptiles Ii Is easy
10 hriug up a character OF minor importance, dsuu-
ruishing birds and reptiles. bui they of very slight
Iuu0rtancc compared with those that distinguish mann
mals and birds. W. find mammals dVlding more ana
more from binds and repues approaching tAen