1871.] 163 [Wilder. 



hypothesis of the "binary composition" of the pollex and primus, in 

 order to get rid of the difficulty caused by their size in man; this 

 makes us all normally sexdigitists; and as no sufficient reasons are given 

 for this part of the view, and as man is the only species in which 

 this special difficulty would arise, and as size is now admitted to be 

 of very slight morphical importance, no one has adopted the view of 

 binary composition of the pollex and primus. 



My own contributions to the solution of this problem originated in 

 the effort to remove the difficulties pointed out by Wyman, by sug- 

 gesting that the morphical value of the manus and pollex was in- 

 versely to their telical importance, and that any difficulty with them 

 should not be allowed to outweigh the teachings of the proximal 

 portions of the membra; this suggestion was contained in my gradua- 

 tion thesis in 1862; and more fully presented in 1865; the same view 

 was advocated in subsequent papers, 51, 52, 57 and 58, together with 

 another respecting the morphical unimportance of the character "nu- 

 merical composition"; both these points, with the distinction between 

 natural attitude and normal position, I regard as demanding careful 

 study in this connection, and they will be discussed hereafter; but in 

 the above papers, I followed Wyman and the rest in comparing the 

 membra in the condition they present in the quadrupeds, which I 

 now believe to be not their normal condition. 



In compliance with the oft-repeated request of former students and 

 others interested in the subject, Prof. Wyman at length completed 

 and published his paper on Symmetry and Homology in Limbs; 55. 

 In the words of a reviewer, ' ' certainly no modern inquirer has 

 searched the secrets of Nature more closely, or clothed his discoveries 

 in more concise and modest language." After showing that " in right 

 and left parts distorted symmetry is the exception, while in the fore 

 and hind (cephalic and caudal) parts of adults it is the rule," 

 Wyman points out the remarkable analogy which exists between 

 symmetry as brought about by vital forces and the effects of physical 

 polarity; then discusses the signification of homology, and concludes, 

 " those parts of the limbs will be homotypes which have the same 

 relative position and are symetrically placed with regard to each 

 other." p. 260. 



He then compares the various parts of the membra as symmetrical 

 structures, "repeating each other in a reversed manner from before 

 backwards as right and left parts do from side to side, because, 

 though open to grave objections, the difficulties met with, are, on the 



