The Origin of Organic Forms. 197 



intelligent results to the blind forces of the environ- 

 ment. But the evolutionist may not question the 

 doctrine ; for " structureless as every germ originally 

 is, the development of an organism out of it is other- 

 wise impossible." 



The same principle is stated more generally else- 

 where. "The change from uniformity into multi- 

 formity in organic aggregates, is caused, as in all 

 inorganic aggregates, by the necessary exposure of 

 their component parts to actions unlike in kind or 

 quality, or both."* 



The process of differentiation by which cells are 

 built up into an organized structure is, according to 

 Mr. Spencer's teaching, due altogether to the environ- 

 ment. The fertilized germ, in certain cases, multiplies 

 by simple fission, increasing the number of cells, but 

 without change in the arrangement of the parts. 

 The difference between the cell splitting up into 

 separate cells, each of them a simple cell and nothing 

 more, and the cell developed into an eagle or an 

 elephant, is due wholly to the incident forces of the 

 environment. The physiological unit is dethroned. 

 It is not easy to see how this doctrine accords with 

 the principle of heredity. It would seem that but 

 for the environing forces every fertilized cell would 

 go on perpetually producing new cells by fission ; in 

 which case the ancestral characteristics must perish. 



* Biology,*Vol. II., 311. 



