Volume I. December, 1887. Number 2. 



JOURNAL 



MORPHOLOGY. 



OOKINESIS. 



C. O. WHITMAN. 



The period of maturation and fecundation of the &^^ is pre- 

 eminently one of kinetic phenomena. We have here two com- 

 plex series of events, which together form the prelude to 

 development. Though overlapping, and blending at the point 

 where development begins, they must, nevertheless, be regarded 

 as distinct, inasmuch as maturation, at least in cases of par- 

 thenogenesis, may be completed quite independently of fecun- 

 dation. 



The phenomena of maturation embrace the closing chapter 

 in the history of the germinal vesicle, and such concomitant 

 changes in the vitelline protoplasm as prepare the o.^'g for the 

 reception of the spermatic element. The phenomena of fecun- 

 dation ^ embrace the history of the pronuclei, and those attend- 

 ant changes in the protoplasm which form the concluding steps 

 in the premorphological organization of the &gg. The first 

 series culminates in the production of polar globules ; the sec- 

 ond, in the formation of the cleavage-nucleus by the union of 

 the pronuclei. In each series we recognize two factors; namely, 

 nuclei and ccll-p7'otoplasm. 



To what extent these factors act independently, and how far 



• The distinction proposed by E. Van Beneden {Arch, de Biol., IV., p. 283) be 

 tween the copulation of the sexual cells and fecundation is here adopted. 



