PLATE 7 
EXPLANATION OF FIGURES 
CEREBRATULU3 
36 Centrifuged at 2nd polar-spindle stage. 
37 Centrifuged egg with delayed polar spindles. 
38 Centrifuged egg segmentation spindle, central rays dislocated. 
39 Centrifuged at 2 pronuclei stage: piece broken off containing pronuclei 
and their attached asters (polyspermic?) 
40 Ditto; another section. 
41 Centrifuged at segmentation spindle stage — one polar aster. 
42 Ditto; bent central spindle. 
43 Ditto; remainder of last and part of lost aster. 
44 Centrifuged at 2d polar body stage (at top of egg) shows displaced spindle. 
45 Centrifuged 25 minutes after setting free, showing displaced nucleus and 
one aster; other represented (?) by the streak near center of egg. 
46 Distorted segmentation spindle after centrifuging; due to yolk pushinji 
it toward center of egg. 
