THE ULTIMATE SEX-ELEMENTS. 



87 



the cell-theory level. To recognise the ovum as a cell, and the 

 spermatozoon as another, to find the starting-point of the 

 organism in the double unity formed from these two, to demon- 

 strate the process of development as one of cell multiplication 

 and arrangement, express great but not final biological facts. 

 Thus it is that of late years, what Michael Foster has called the 

 "protoplasmic movement" has made itself felt, not only in 

 study of the general functions of the body, but in the special 

 physiology of the reproductive cells and their history. Even 

 in morphological or structural studies, attention has shifted 

 from the shapes of cells to the structure of their living matter, 

 or from the different forms of ovum and spermatozoon to the 

 germinal protoplasm or Keimplasma which they contain. On 



Ground Plan of Protoplasmic Changes. 



this level, in fact wliere biology has touched the bottom, 

 morphology and physiology have become more than ever 

 inseparable. All the facts of structure on the one hand, and of 

 function on the other, have both to be interpreted in terms of 

 the constructive and disruptive changes in the living matter 

 itself. The general theory may be summarised in the accom- 

 panying diagram. Protoplasm is regarded as an exceedingly 

 complex and unstable compound, undergoing continual mole- 



