WN Spa 
ONS NAG 13? 
DYNAN 1/47 330 
da | AeGBy 
ee 
eps BEehrv 
ESF TIWSS SB 
LAT ANNS OLS 
BEL! KS: 
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CPs S530 
SRS 
Fic. 12.—Maturation of the egg of Cyclops (the full number of chromo- 
somes is not shown): A, germinal vesicle with the chromosomes 
already split longitudinally. B, the chromatin masses shortened, 
with indication of transverse division to form the tetrads. C, the 
young tetrads arranging themselves on the first polar-body spindle. 
D, tetrads in first polar-body spindle. E, separation of the dyads 
in the same. F, position of the dyads in second polar-body spindle ; 
the first polar body is shown above the margin of the egg. (After 
Rickert.) 
182 
