Smallwood. — Maturation Haminea. 



PLATE 12. 



Fig. 81. First cleavage spindle. Tiie cliromosomes are becoming arranged in the 

 equatorial plane of the spindle. The coarse chromatin granules are 

 becoming diffused in the cytoplasm. X 1G80. 



F^ig. 82. Transverse division of chromosomes in first cleavage. X 1224. 



Fig. 83. Anaphase of second maturation division. The outer centrosome has dis- 

 appeared, and the inner one is very faint (too prominent in the 

 rei)roduced figure). Brazilin. X 1224. 



Fig. 84. Tlie chromosomes of the female pronucleus have become vesicular and lie 

 in a cluster around the fading centrosome. The male pronucleus has 

 a thick wall and contains chromatin granules and linin fibres. Iron 

 haeniatoxylin and Bordeau.x red. X 1224. 



Fig. 85. Astral rays of the deep second maturation aster still persist. Male and 

 female pronuclei lie close together ; each much lobed owing to incom- 

 plete fusion of the nuclear vesicles, and containing a definite linin 

 network. Iron haematoxylin. X 1224. 



Fig. 86. First cleavage spindle. Compare description of Figure 81. 



Figs. 87, 88. Prophase of first cleavage. Tiie cleavage asters are not connected 

 with each other, but each is associated with a single pronucleus. The 

 chromatin of the chromosomes is solid. Tiie rest of the ciiromatin 

 exists in the form of rings. Iron haematoxyliu and Bordeaux red. 

 X 1080. 



