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THE AMEBIC AN NATUBAL1ST [Vol. LIV 



It is by no means anticipated that the conception of the 

 transmissibility of characters as so many accelerated 

 adaptive responses, involving new structural inter-rela- 

 tionships, and not necessarily with factorial germinal 

 representation, will apply to all the features of an or- 

 ganism and serve as an explanation of the origin of heri- 

 table characters generally. Its application may be lim- 

 ited to such as have an adaptive significance, and can be 

 assumed to have arisen in the first instance as a result of 

 internal or external stimuli acting upon the soma. As 

 will be shown in a later paper the ostrich itself, especially 

 in the details of its degeneration, presents us with many 

 character changes which have manifestly no adaptive 

 significance, but are the expression of germinal changes, 

 uninfluenced by external forces. Without question we 

 are short-sighted in attempting to reduce the methods of 

 evolution to some common term; as Professor H. F. 

 Osborn points out in his new book: "The Origin and 

 Evolution of Life," 14 there are centripetal factors in or- 

 ganic evolution, there are centrifugal factors. Much of 

 the recent work on Mendelism and mutation strongly 

 supports the view so warmly advocated by Professor W. 

 Bateson and Professor T. H. Morgan that germinal char- 

 acters appear apart from any adaptive considerations, 

 and the degenerative changes in the ostrich are in full 

 accord with this ; but it is by no means a complete answer 

 to the problems of evolution, where so much appears that 

 is directly adaptive and so little that is non-adaptive. 

 Most genetical work during the present century has been 

 micHimceted with adaptation, yet it is one of the big 

 problems of biology which calls for solution as insistently 

 as ever, and it may be that a proper interpretation of the 

 callosities in the ostrich will assist in some measure 

 towards an understanding. 



