Smallwood. — Maturation Haminea. 



PLATE 8. 



Fig. 50. Late anaphase of second maturation. The whole centrosome is very 

 faint. Iron haematoxylin and Bordeaux red. X 1224. 



Fig. 51. The cliromatin of the female pronucleus is in the sponge-work stage. 

 Iron iiaematoxylin. X 1224. 



Fig. 52. Anaphase of second maturation. Minute centriole present in flattened 

 centrosome. Iron haematoxylin and Bordeaux red. X 1224. 



Fig. 53. Tiie male pronucleus lies near the centre of the egg. Interzonal 

 filaments still connect the second polar cell with the female pronucleus. 

 Division of the first polar cell nearly completed, and exhibiting a 

 small midbody. Iron hasmatoxylin and Bordeaux red. X 1224. 



Fig. 54. Second maturation figure. The centrosome composed of centriole and 

 centroplasm. Sphere-substance differentiated into medullary and 

 cortical layers. Spindle very long, but incomplete. Fine fibres grow- 

 ing out from chromosomes toward centrosomes. Brazilin. X 1224. 



Fig. 55. Second maturation. Spindle elongated still more and nearly complete. 

 Outer centrosome still homogeneous. Inner one differentiated into 

 centriole and centroplasm. Brazilin. X 1224. 



Figs. 56, 57. The sperm head at the beginning of its migration. Vacuolation 

 has not yet taken place in it. Delafield's hasmatoxylin and picric 

 acid. X 1680. 



