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LILLIE. 



[VOL. I. 



The black granules in the inner sphere of Fig. jE are plainly 

 much less in bulk than those of Fig. jB, e.g. There is no 

 doubt that a large part of the centrosome granules has been 

 changed into the red-staining substance of the sphere, which 

 is identical in all noticeable respects with the substance from 



FIG. 7. A-E are horizontal sections through the outer aster of the second maturation 

 spindle, illustrating the phases of the centrosome from a stage slightly before that of 

 Fig. 5 to the metaphase. B, C, and D are not necessarily successive stages, but 

 simply different conditions met with between stages A and E. F is from a radial 

 section of the inner aster in the beginning of the anaphase ; this condition of the 

 centrosome follows immediately ; and precedes the stage of Fig. 6. 



which the central spindle was formed. And in a later stage 

 one sees the fibers of the central spindle dotted with large black 

 microsomes. 



From this description it would seem to follow that the cen- 

 trosome of one cell-generation becomes the inner sphere of the 

 next ; and this is undoubtedly true at times. But I do not 



