1918] Yocum: The Neuromotor Apparatus of Enplotes Patella 387 



as found in metazoan germ cells. After this contraction the macro- 

 nucleus elongates and divides amitotically, half going to each of the 

 daughter organisms. 



4. At the time of division the new neuromotor apparatus is formed 

 independently of the old one, by a differentiation of the ectoplasm. 

 The old motorium persists as the motorium of the anterior daughter 

 Euplotes and the cytosome in the anterior part remains. All cirri are 

 formed anew and the old cirri and connecting fibers are absorbed. 

 The new cytostome forms independently of the old cytostome. 



5. The changes undergone by the organism at the time of binary 

 fission indicate a dedifferentiation of the cytoplasm followed by a 

 rejuvenescence and differentiation into new structures. The macro- 

 nucleus, which is the controlling organ of the metabolic activities, 

 undergoes a corresponding reorganization in order to govern properly 

 the increased metabolism of the rejuvenated organism. 



6. The structural relationships of the blepharoplast to the motor 

 organs of flagellates and of the motorium to the motor organs of 

 ciliates and the connection between the blepharoplast and nucleus in 

 flagellates, and the indication of such a connection in some ciliates 

 suggests that the neuromotor apparatus in flagellates and ciliates are 

 homologous structures. 



