MATURATION AND IMPREGNATION OF THE OVUM. 533 



of the spindle an intermediate one is found in which a spindle 

 can no longer be seen in the egg, but its place is taken by a com- 

 pact rounded body. He has not been able to arrive at a conclu- 

 sion as to what meaning is to be attached to this occurrence. In 

 any case the spindle which projects into the prominence on the 

 surface of the egg divides it into two parts, one in the prominence 

 and one in the egg (Fig. 7). The prominence itself with the 



;&&%$ 



. oo'a .">: o-'-- 

 figglS 



$&'' '4 



?->*: 



i c*-.' c ^ 



|^-. ; .o;V;'';.i" 



^:v^S^ 

 ?^Xf?:f- 



FIG. 7. Portion of the ovum of Asterias glacialis at the moment of the detachment 

 of the first polar body and the withdrawal of the remaining part of the spindle 

 within the ovum. Picric acid preparation (copied from Fol). 



enclosed portion of the spindle becomes partially constricted off 

 from the egg as the first polar body (Fig. 8). The part of the 



FIG. 8. Portion of the ovum of Asterias glacialis, with the first polar body as it 

 appears when living (copied from Fol). 



spindle which remains in the egg becomes directly converted into 

 a second spindle by the elongation of its fibres without passing 

 through a typical nuclear condition. A second polar cell next 

 becomes formed in the same manner as the first (Fig. 9), and 



FIG. 9. Portion of the ovum of Asterias glacialis immediately after the formation of 

 the second polar body. Picric acid preparation (copied from Fol). 



