OSTEOLOGY OF THE CATHARTIDA. 
By R. W. SHUFELDT, M. D. 
Captain, Medical Department, U.S. Army. 
Noswithstanding the fact that living birds, taken as a class, form one 
of the best isolated groups we have in nature, their arrangement into 
families and the division of these families into genera is still on a very 
unsatisfactory basis. This, no doubt, has been largely due to the fact 
that all of the variously proposed classifications have rested almost ex- 
clusively upon external characters; only an anthor here and there point- 
ing out in his writings differences in internal structure. Of recent years, 
however, this imperfect system and highly uncertain course has been 
very much modified and improved by the attention given to avian anat- 
ony by quite a number of earnest and painstaking zootomists. The 
published labors of these gentlemen and the facts they have succeeded 
‘in elucidating have already made their impression upon the problem to 
be solved, and in many cases the family lines are now more sharply 
defined. 
We must all agree, though, that this good work is yet in its infancy, 
and that the question of the classification of birds can only be definitely 
se.tled when we are thoroughly familiar with the habits, external 
structure, and characteristics of each species, and these are combined 
with a complete knowledge of their internal anatomy in all of its minutest 
details. The classification resting upon the digested and compared 
facts of such a knowledge as this can be the only perfect one, and the 
only one that will not be subject to sudden surprises and consequent 
changes, rendered necessary by periodical discoveries in structure and 
the development of new anatomical facts. In short, as distant as the 
day may seem, we will only be able to devise a perfect classification of 
living objects in nature when we have mastered their anatomy, using 
the word in its broadest sense. So that well-established and recorded 
anatomical data become particularly valuable to descriptive zoologists, 
and we feel sure that itis the aim of every one interested in this im- 
portant subject to further the efforts of those now engaged in this par- 
ticular branch of the science, in anyway in their power, in order to 
meet the end in view. Probably there is no better illustration afforded 
us anywhere in the recent literature of the science of ornithology, in 
which anatomy has played a more prominent part in deciding classifi- 
ceatory division, than in the separation of the Cathartide from the Old 
World Vultures, nor in none, if it had continued to be relied upon, where 
simple external characteristics could have been more misleading. In 
this particular instance the osseous system was the one that finally ren- 
- dered the principal assistance in determining the dividing line. 
Accepting as we must, then, these prerequisites to a sound classifica- 
tion, how idle it is for any one to attempt to define permanent family 
lines that will stand the test of time and research by any single set of 
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