PLATE 6 



EXPLANATION OP FIGURES 



55 Formation of 'bouquet' stage in male pronucleus. Appearance of several 

 plasmosomes. (X 1700) 



56 Chromosomes of female pronucleus beginning to break up. (X 1700) 



57 'Bouquet' formed in both pronuclei. The centrosomes of male origin 

 taking up a position midway between the two nuclei. (X 1700) 



58 Formation of diffuse spireme in both pronuclei. Centrosomes beginning 

 to separate. (X 1700) 



59 Two pronuclei lying side by side in the egg. Centrosomes widely sepa- 

 rated. (X 1700) 



60 Two pronuclei in apposition. Chromatic network breaking down and 

 discrete chromosomes being formed. Fusion of plasmosomes into one large 

 body. (X 1700) 



596 



