24 Vitality and Organization of Protoplasm. 



as to constitute idants ; — how, then, it must he asked, can these spe- 

 cifically arranged gToups of divers biophores themselves multiply by 

 self-division? How can the two resulting halves contain an equal as- 

 sortment of all necessary determinants, without which no continuity 

 of germ-plasm can exist, and without which the entire theory is vitiated 

 in its most essential assumption? It is true that the chromosomes 

 themselves, conceievd as idants, are actually seen longitudinally to di- 

 vide. But no appearance points to their really consisting of so com- 

 plex an aggregational structure as is here hypothetically assumed. Di- 

 vision of determinants, ids and idants into two equal halves, under the 

 supposition that they are composed of a diversity of self-dividing bio- 

 phores, is simply inconceivable, as has been already stated in reference 

 to any kind of specifically arranged group of diversified units. But 

 Weismann's theory rests essentially on such equal division of specific- 

 ally arranged groups of diversified units. For onl}^ division into equal 

 halves can furnish successive generations with complete assortments 



, of determinants ; can, in fact, secure the continuity of the germ-plasm. 

 Equal division of Weismann's germ-plasm being inconceivable, his theory 

 is left without a sound foundation. 



It would be therefore superfluous to expose the fallacies involved in 

 additional assumptions that have to be made in order first to consti- 

 tute the manifold different groups of biophores; and then to marshal 

 them in their way to achieve the stupendous task of constructing the 

 adult organism with all its peculiarities of structure and function.* 



As regards the alleged unequal division of germ-plasm during onto- 

 genetic evolution, which forms an essential tenet of Weismann's theory, 

 it is effectively refuted by the demonstration of the formative totipo- 



jtence of fragments of egg-plasm. This important discovery upsets, 

 indeed, all his ingenious groupings of biophores, together with their 

 surmised ontogenetic potencies. 



It may here again be pointed out with advantage, that vital units, 

 such as biophores are supposed to be, conceived as bearers of all essen- 

 tial vital properties, are thereby constituted also bearers of the real 

 process and entire secret of ontogenetic evolution. For their own propa- 

 gation by means of self-division consists in the complete ontogenetic 

 reproduction of new beings. They must therefore contain within them- 

 selves all potencies that come into play during ontogenetic evolution 

 and that underly the hereditary transmission of parental traits. And 

 as the entire ontogenetic evolution of the complex adult organism is here 

 wholly effected by the grouped progeny of proliferating biophores, the 

 problem of ontogenetic evolution would, under this view, have to be 

 solved, if it can be solved at all, not by making imaginary vital units 

 hypothetically multiply and automatically group themselves into the 

 organized form of the adult organism ; but by showing how the ])hyletic 



*This the present writer has to some extent attempted in a paper on "Mole- 

 cular theories of organic reproduction," read before the Texas Academy of Sci- 

 ence, December, 1805. 



