PLATE IX. 
ILLUSTRATING THE PAPER OF BRADNEY B. GRIFFIN, p. 163. 
Fic. 1. The egg ten minutes after fertilization, showing the minute asters 
and their focal centrosomes, also the large black nucleolus. 
Fic. 2. Somewhat later stage several tetrad groups have been already 
formed. F 
Fic. 3. The same stage, showing variation in relation of asters to nucleus. 
Fic. 4. Much later stage. The tetrad groups have now been established, 
leaving a mass of discarded chromatin. The sperm head is shown at . 
Fic. 5. First polar spindle during halving of tetrads. Sperm head at ¢. 
Fic. 6. First polar telophase. Sperm head and aster ( ¢ ). 
