3o8 



GERMINAL ORGANIZATION 



INDUCTION PHENOMENA 



the motility of the spermatozoon. This equipment of the male gamete implies 

 polarization and even the acquisition of a bilateral symmetrical structure, and 

 testifies the presence of the mechanisms necessary for cyto-differentiation. However 



^ r 



Fig. I. Conspicuous mitochondria in growing oocytes of the hamster. Ahmann technique. 

 Four stages are presented, stages A B D in Fig. la, stage C in Fig. ib. A. Stage of incipient 

 growth: the cytoplasm is made completely opaque by mitochondria; the clear spot is a 

 vesicle of nuclear sap expelled from the nucleus. B. young primary follicle : the mitochondria 

 of the egg are somewhat more dispersed; nucleus below, polarization already distinct. 

 C. Secondary follicle: a rather large amount of cytoplasm has been formed; mitochondria, 

 mainly peripheral, are still quite abundant; the clear vesicle to the right of the nucleus 

 is also an emission of nuclear sap. D. More advanced secondary follicle, with the mitochon- 

 dria beginning to disperse (Dalcq and Van Egmond, 1953). 



