Smallwood. — Maturation Hamiuea. 



PLATE 13. 



All preparations stained with iron htematoxylin and Bordeaux red. 



Figs. 89, 90. Prophase of first cleavage. The cleavage asters are not yet con- 

 nected with each other, but are associated one with each pronucleus. 

 The chromatin of tiie chromosomes is solid (Fig. 89) or vesicular 

 (Fig. 90). Tiie rest of the chromatin exists in the form of rings. 

 There is a tiiin layer of spliere-substance around each centrosome. 

 X 1680. 



Fig. 91. Telophase of first cleavage. Tiic chromosomes have fused into irregular 

 nuclei. The astral rays directed toward the disappearing centrosome. 

 X 1224. 



Fig. 92. Anaphase of first cleavage. Part of the chromosomes vesicular. Centro- 

 some still present, but irregular in outline. Thickenings on interzonal 

 filaments. X 1224. 



Fig. 93. Prophase of first cleavage. The solid black bodies are chromosomes. 

 Tlie cytoplasm in the region of the deutoplasm takes a deep stain. 

 X 1680. 



Fig. 94. Centrosome, cut parallel to axis of spindle, composed of centriole and 

 centroplasni. Spliere-substance differentiated into medullary and cor- 

 tical layers. X 1680. 



Fig. 95. Composite figure, from three sections of the incompletely fused nuclear 

 vesicles derived from the chromosomes. First cleavage. X 2733. 



Fig. 96. Prophase of second cleavage. Cleavage asters independent of each other, 

 and lying at different levels in the section. X 1224. 



Fig. 97. Quiescent nuclei in two-cell stage. Interzonal filaments and midbody 

 present. X 1224. 



Fig. 98. Prophase of third cleavage. Asters independent of each other. Cyto- 

 plasm takes a deep stain in region of deutoplasm. X 1224. 



