A DYNAMICAL HYPOTHESIS OF INHERITANCE. 25 



well as the numerous subsidiary hypotheses that must be 

 worked out to support it, will be fatal to it as a system. 



The path along which the solution of the problem of 

 heredity is to be effected lies in a wholly different direction, 

 namely, in that of the study of the mechanics and dynamics of 

 development, and in the resolute refusal . to acknowledge the 

 existence of anything in the nature of preformed organs or of 

 infinitesimal gemmules of any kind whatsoever. Such devices 

 are unnecessary and a hindrance to real progress in the solu- 

 tion of the questions of inheritance. They only serve to divert 

 the attention of the observer from the real phenomena in their 

 totality to a series of subordinate details, as has happened in 

 Weismann's case. All this while he has been watching the 

 results of an epigenetic process, as displayed by an inconceiva- 

 bly complex mechanism in continuous transformation, and out 

 of all of this the most essential thing he has witnessed has 

 been one of the effects of the operation of that contrivance, in 

 the mere splitting of chromosomes that are his " ids," 

 "idants," "biophors," etc. The potentiality of the part has 

 been mistaken for that of the whole. 



We must dismiss from our minds all imaginary corpuscles 

 as bearers of hereditary powers, except the actual chemical] 

 metameric or polymeric molecules of living matter, as built up 

 into ultramicroscopic structures, if we wish to frame an 

 hypothesis of heredity that is in accord with the requirements 

 of dynamical theory. The " discovering " and naming of 

 "ids," "biophors," and "pangenes," time will show to have 

 been about as profitable as sorting snow-flakes with a hot spoon. 

 We must also dismiss the idea that the powers of development 

 are concentrated in some particular part of the germ-cell, nor 

 can we assume the latter to be homogeneous. 1 This we are 



1 The writer finds himself unable to agree with Haacke, if he has properly un- 

 derstood that author's assumption as to the homogeneity or monotonous character 

 of living matter, as set forth in his admirable work Gestaltung und Vererbung, 

 1893. Nor does it appear that anything is gained by the acceptance of Haacke's 

 theory of Gemmaria, that is not easily understood upon the far simpler grounds 

 that will be set forth here, though there is much in the book cited with which 

 epigenesists must agree, aside from the weighty character of its criticisms and its 

 pregnant suggestiveness. 



