60 THE SURVIVAL OP THE UNLIKE. [ll. 



scientific world have for their particular object the ex- 

 planation of the assumed progressive tendency of the 

 forms of life. 



It is incomprehensible that the minute fertilized ovum 

 or egg-cell should reconstruct the essential characters of 

 the two individuals from which it pro(;eeds, unless it has 

 in some way derived distinct impressions from every part 

 and organ of the parental bodies which it is to reproduce. 

 It would seem as if it must of itself be an epitome or con - 

 densation of its parents, with the power of unfolding its 

 impressions or attributes during the' whole life -course of 

 the organism to which it gives rise. Several hypothe- 

 ses have been announced to account for the phenomena 

 of heredity, of which one of the most important is still 

 Darwin's theory of pangenesis. Darwin supposed, pro- 

 visionally, that besides the ordinary multiplication of the 

 cell, each cell may "throw off minute granules which are 

 dispersed throughout the whole system; that these, when 

 supplied with proper nutriment, multiply by self -divi- 

 sion, and are ultimately developed into units like those 

 from which they were originally derived." These gran- 

 ules, or gemmules, have a natural affinity for each other, 

 and they collect themselves "from all parts of the sys- 

 tem" to form the sexual materials or elements. These 

 sexual elements, therefore, which unite to form the new 

 individual, are an epitomized compound of the parents. 

 The value of this hypothesis, it seems to me, lies not so 

 much in the particular constitution and behavior of these 

 gemmules, as in the fact that it attempts to account for 

 the known phenomena of life by supposing each corpo- 

 real element to be represented in the sexual elements. 

 The hypothesis has never gained wide support, because 

 of the supposed physical improbability of the gemmules 



