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ON THE CLASSIFICATION OF BIRDS. 



outward organisation. The study of the first is not so 

 essential to the zoologist as that of the last ; and, al- 

 though both are intimately connected, they may be, 

 and have been, pursued separately. It is, for instance, 

 by no means necessary for the clear understanding of 

 the ruminating quadrupeds, that the naturalist should 

 be informed that they possess more stomachs than any 

 other animal ; nor is it essential to his object of denning 

 and classifying them, that he should know which species 

 ruminate their food, and which do not. But were he 

 to neglect the study of the external anatomy of these 

 beasts, and disregard the form, direction, and substance 

 of their horns, the size and situation of their teeth, and 

 other parts of their external anatomy, he would be ut- 

 terly unable to proceed ; nay, more — he would be scarcely 

 able to define what difference there was between an ox 

 and an elephant. As with quadrupeds, so with birds. 

 The form of structure of the body, and all its various 

 members, is comprised under the head of external ana- 

 tomy ; and it is from the various modifications and 

 appearances which these parts assume, that the ornitho- 

 logist is capable of drawing such discriminating charac- 

 ters as enable him to form clear conceptions of their 

 respective peculiarities. Were he, on the other hand, to 

 make their internal anatomy the basis of his system, he 

 might be able to classify those native birds which, from 

 being common, might be procured for dissection ; but 

 thousands of others must be left undetermined : and 

 after all, however elaborate might be his system, it would 

 be utterly useless for practical purposes, and unintelligible 

 to all but professed anatomists. It has generally hap- 

 pened, that those who have attached so much fancied 

 importance to the internal anatomy of animals, have 

 been but very imperfectly acquainted with the habits 

 and economy of the animals themselves ; and thus, while 

 we have had the most minute details of their internal 

 conformation, we have been left in comparative igno- 

 rance of those especial purposes for which each particular 

 structure was intended : just as if we described, with 



