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STANLEY C. BALL 



with the absence of any polar body, stamps it as the first polar 

 spindle. Its appearance thus before the egg has been enclosed 

 in its capsule is believed to be unusual. 



The first maturation spmdle typically appears after the two 

 ova and their yolk cells have been encapsulated. At the time 

 of its greatest length the spindle occupies nearly the entire polar 



Text fig. 5 Section of a capsule containing in the yolk a vacuole filled with 

 spermatozoa, emb., embryo; sp., spermatozoa. X 400. 



Text fig. 6 Reconstructed section in a plane perpendicular to actual sections 

 through a capsule containing an egg which has given.off both polar bodies, cap., 

 capsule; d.y.n., degenerating yolk cell nuclei; inf., infiltration; p.b.l, p.h.2, 

 first and second polar bodies; y, yolk; y.c, yolk cells. X 730. 



diameter of the egg (text fig. 8) Each centriole appears as a 

 tiny dot in the center of a large centrosphere, from which radiate 

 the conspicuous astral rays. Owing to the minuteness of the 

 chromosomes, and the extreme difficulty in obtaining all the 

 stages of the process of maturation, it is hard to determine in 

 any given case just what phase they represent. One must 

 depend rather on the presence or absence of polar bodies and 



