S7 



<t 



REGENERATION 183 



division.* These experiments and others to be 

 shortly alluded to seem to dispose of what is 

 known as evolution in the ovum, and tp_ 

 establish epigenesis.'f There have always been Evolution 

 two tTieofles^as to the impregnated ovum,J the an ^ 

 first of which evolution assumes that the e] 

 new individual is contained in the ovum as 

 such and only requires unfolding. The extreme 

 view of this was to be found in the ancient 

 and, since the discovery of the microscope, 

 exploded theory of emboitement. According 

 to this, each generation in perpetuity was con- 

 tained in any ovum, an idea which involves 

 ) an obvious absurdity. But it exists in another 

 form, that is, under the idea that the embryo 

 exists, so to speak, in the form of _a Develop- 

 able machine and that the process, though not 

 so crude as that just alluded to, is none the 

 less a process of unfolding a new but preformed 

 .individual. The other theory implies to put 



* Heterologous twins under this theory are the product of 

 two ova a case of superoetation. 



t Evolution in this connection has nothing whatever to say 

 to evolution in the commonly understood or Darwinian sense. 



$ Apart, of course, from the old divisions of Spermatists 

 and Ovulists of historic interest only since the microscope 

 came into existence. The former to put things simply 

 looked upon the spermatozoon as the plant and the ovum 

 as the pot in which it grew; the latter thought that the 

 ovum was the important factor and that the spermatozoon 

 merely incited it to action. The latter view, under another 

 form, has recently come into some notice, as will be seen 

 when the question of Parthenogenesis comes under con- 

 sideration. 



