44 



MORPHOGENESIS IN CILIATES 



In Foettingeria, a, h, and c are formed anew from the 

 kinetosomes produced by the kinety 1. In Chromidina ele- 

 gans the whole ''oral" system a, b, c, x, y, z is absent in the 

 trophont. It is formed during palintomy from the kineto- 



FiG. 15. Pericaryon cesticola. Kineties y and z are reduced to two 

 kinetosomes; kinety x to one kinetosome. 



somes derived from 1. This is a unique example among the 

 ciliates of the formation de novo during one phase — tomite 

 — of the oral ciliature absent during another phase — tro- 

 phont. Some sort of regulation therefore exists. 



These kinetosomes originating from one kinety behave 

 differently from the mother kinetosomes which have re- 

 mained in line in the mother kinety. Once again, we reach 



