ON MORPHOLOGY AND TELEOLOGY, ESPECIALLY IN THE LIMBS OF MAMMALIA. 



BY BURT G. WILDER, S. B. 



Read June 3d, 1863. / '- , 



IT is not many years since the very title of this paper would have been enough to 'insure 

 its remaining unread by most professional men, or, if read, to excite their derision of him 

 who should have so wasted his time as to write, or even think, of such vain abstractions, fit 

 expressions of the useless imaginings of the half-crazy enthusiast Oken, and his only less 

 crazy, because less gifted, disciples. And there are, even now, stern votaries of practical 

 science who would scorn any attempt to raise their eyes above the mere facts of Nature 

 which are as patent to the ignorant vision as to their own, and who refuse to seek an 

 insight into those hidden relations, for the correct understanding of which their superior 

 knowledge might be the surest preparation. 



But there are others, and their number is increasing, who, believing in the existence of a 

 general plan underlying all the more external phenomena of Nature, are willing to try to 

 comprehend it in its greater and lesser manifestations ; and they, in reading the " Physio- 

 philosophy," may .be able to discern, amongst much that is fanciful and absurd, many sug- 

 gestions of a sound as well as original and striking philosophy. No apology, therefore, is 

 now required for thinking or writing upon subjects which have engaged the attention of 

 the most celebrated students of both animal and vegetable anatomy, and which, I am con- 

 vinced, will, erelong, be acknowledged to be as essential to the proper understanding of 

 these sciences as the classifications of which they form the only true basis. 



To express the various relations which have been observed among the several parts and 

 their functions, of animals and plants, the following terms have gradually come into use : 

 homology, affinity, morphology, analogy, teleology ; to these may be added physiology, which, 

 though a term long employed to denote the general study of function, has now acquired 

 a certain technical significance, equivalent to the more strictly scientific, and therefore 

 preferable term, teleology. 



Analogy is used to indicate similarity of function, which may be very close, when yet the 

 two parts are widely dissimilar in structure ; as, for instance, the organs of aerial locomotion 

 of a bird and a butterfly, which both go by the name of wings, though one is built upon the 

 vertebrate, and the other upon the articulate plan of structure. Of course the structure 

 may correspond with the external form and function, and then the analogy is more com- 

 plete, as between the foot of man and that of a bear. 



Now the general function or use of a part is its physiology ; the special or principal use of 

 a part is its final cause or end, or teleology ; and parts which are teleologically similar are 

 said to be analogous. 



It is evident that the external form and the function must to a great extent correspond, at 

 least much more fully than either may with the internal structure, and here we observe the 

 first distinction between the two groups of terms given above ; for this intimate structure 

 and arrangement, in other words, the pure anatomy of anything, is its morphology, and parts 

 which are morphologically similar are said to be homologous ; there is homology or affinity, or, 

 in still plainer words, more or less identity of structure between them ; and here again, as was 

 seen in speaking of analogy, parts or organs which are homologous, that is, identical in their 



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