1871.] 325 [Wilder. 



lieve in telical suppression of a phalanx in one case, and a similar redundancy 

 of phalanges in the other case. If I undertake to compare the manus of a bird 

 with its pes, either antitropically or otherwise, I must admit with every single 

 digit a difference in the numerical composition of its homologue. Until our 

 morphological insight has penetrated far enough for the solution of such prob- 

 lems as these, it seems perfectly reasonable to maintain that the objections on 

 the score of numerical composition that have been urged against the antitropic 

 homology of pollex with quintus, and of minimus with primus, apply with 

 manifold force to a majority of the, homologies that anatomists consider de- 

 termined." 



V. GENERAL PROBLEMS. 



The radical difference of opinion respecting the rnorpliical rela- 

 tions of membra which the historical sketch exhibits between such 

 Syntropists as Owen, for instance, and such Antitropists as Wyman, 

 is not to be accounted for by any assumption of difference in their 

 knowledge of facts or their intellectual power, but rather, as it 

 seems to me, by a recognition of the dissimilarity of the premises 

 which they have admitted, and the methods of reasoning which they 

 have followed : in the one case, the human body has been chiefly em- 

 ployed in making the comparison, and attention has been early di- 

 verted to the correspondence of the pollex with the primus in respect 

 to size, numerical composition and relative position, when the manus 

 is in its natural attitude of pronation, as with many quadrupeds. In 

 the other case, more attention has been given to the telical antago- 

 nism of the ancon and genu with many animals, and to the relative 

 position of the membra during the early stages of development. 



In more general terms, the idea of Syntropy is based upon the ob- 

 vious resemblance in respect to size, numerical composition and natural 

 attitude of certain highly specialized parts of peripheral organs belong- 

 ing to animals of high zoological rank, and in the adult condition; 

 while the idea of Antitropy is based upon the antagonism of relative 

 position of proximal and less specialized parts with animals lower in 

 rank or at earlier stages of development 1 



Now, without doubt, the question under discussion is primarily one 

 of structure rather than of function ; it is a morphological and not a te- 

 leological problem. Before it can be solved, it is evident that we must 

 first ascertain which are correct of the two groups of premises above 



i These ideas were advanced by me in part in 45, 21, and more distinctly in 57, 

 (Props. 9 and 10). 



