106 Dr. E. W. Shufeidt on the 



morphological system, as indicating interexisting affinities, 

 that value is certain to be affected when the facts brought out 

 by a study of another system, as the muscular system, for 

 exanijde, are applied to it. As evident as this is, however, 

 we have not far to seek in order to discover avian classifiers 

 who would be content to base their taxonomic scheme of the 

 class upon some single character of some special system, as, 

 for instance, De Blainville did in using only the body of the 

 sternum for the purpose. Such a practice lands one not very 

 far from the plane arrived at by Pliny in the first century. 



Dr. Alfred K.ussel Wallace, in criticizing a memoir of 

 Mr. Blanch ard's in * The Ibis ' for the year 1864, says very 

 truly that we should make the greatest errors in classification 

 by following the sternum alone, as, " for example, the sterna 

 of the Finches and the Flycatchers are scarcely distinguish- 

 able, notwithstanding the great dissimilarity in almost every 

 part of the structure of these birds — their bills, their feet, their 

 plumage, their habits, food, and digestive organs. On the 

 other hand, the sterna of the several genera of the Capri- 

 mulgidje differ from each other more than those of the most 

 distinct families of the restricted Passeres. Tiie Bee-eaters, 

 the Barbets, and the Woodpeckers, again, are three very 

 distinct families, which, in a classification founded upon ail 

 parts of a bird's organization, cannot be brought in close 

 contact; and yet their sterna, according to Mr. Blanchard, 

 much resemble each other. It is evident, therefore, that the 

 whole structure of a bird and its corresponding habits may be 

 profoundly modified, and yet the sternum [may retain a 

 very close resemblance to a common form ; and, on the 

 other hand, the sternum] * may undergo important changes, 

 while the general organization and habits are but little 

 altered." So much for the value of single anatomical 

 systems in avian taxonomy, and so much for the value of 

 single characters in any system. Now as to the value of 

 osteology as a whole in the classification of birds, no ornitho- 

 tomist or classifier of this group of vertebrates will for a 

 moment doubt. Employed in its entirety the osseous system 

 of Aves stands far in advance of any other in settling the 

 question of affinities and affording characters in classification. 

 It has been almost entirely through our studies of the fossil 

 skeletons of birds that we have been enabled to fix their 

 origin in time or to link them with their extinct reptiliaa 

 ancestors. 



* [The passage between brackets is as it stands in ' Ibis/ and has 

 probably been omitted by accident in the Proc. Ac. Nat. Sc. Phil. — Eds.] 



