74 



MORPHOGENESIS IN CILIATES 



the proter's mouth. As has been correctly noted by V. 

 Tartar (1941), '^Clearly differentiation and dedifferentiation 

 are here not conditions which characterize the cell as a 



Fig. 30. Euplotes patella, (a) Ciliate in vivo, ci-cs, posterior cirrhi; 

 C.I., longitudinal crest; /1-/9, frontal cirrhi; /., undulating membrane; 

 p., pulsola; ti-to, transverse cirrhi; z.p., preoral zone, (b) Young 

 ciliate. (c)-(f) Predividing form, showing the new cirrhi and new net- 

 work. The peristome of the opisthe is formed from one kinetosome 

 originating from the posterior sector of the parental peristome, .e.z., 

 developing oral zone of the opisthe; n.c, new cirrhi; n.z., new network. 



whole but are quite local events which may occur simul- 

 taneously in different regions of the cell." It is quite obvi- 

 ous that many organelles are unable to divide. The "ro- 

 sette" of the apostomes lacks this ability. A new rosette 



