Smallwood. — Maturation Haminea. 



PLATE 4. 



Figs. 19-22. Metaphase of first maturation spindle. Cliromosomes mostly rod- 

 like. Centrosome differentiated into centriole and centroplasm. Sphere- 

 substance composed of a medullary and a cortical layer. Iron lisema- 

 toxylin and Bordeaux red. X 1920. 



Fig. 23. A section of the centrosome. Centriole large and irregular in outline. 

 Centroplasm crenate, projecting out in the direction of some of the 

 astral rays. Medullary layer takes a faint plasma stain. Iron haema- 

 toxylin. X 1920. 



Fig. 24. A cross-section of the first maturation spindle in the metaphase. Sixteen 

 chromosomes. Fibres of central spindle show as fine dots between the 

 chromosomes. Iron haenmtoxylin. X 1224. 



