(^pron. 



se^.fuccl 



Fiij. i4L>, The matuiiiliur) ;iiid impri;gnyliijii of thf animal ovum (diagrammatic''. 



A. the O'N'uin, surrounded hy the vitelline membrane (mcni)^ in the act of form in y; 

 tlic (irst polar cell (/('<); ^ cent, cenlrosoint:. B, Ijoth polar cells K pol) air; 

 formed, ihe female pronucleus (9 proii.) lies near the centre of the ovum, and 

 one of the several sperms is shown making its way into the o\ um at the micropylc 

 {viicrop), C, the head of the sperm has Ijecome the male pronnclt:us {6 pron), 

 its intermediate piece the male centrosome H cciii)\ other structures as before. 

 f), the male and female pronuclei are in the act of conjugation. 10, conjugation 

 !.-, complete, and the segmentation nucleus {scg. iiticl) formed. (l'"rnin J'arker 

 and Haswell's Zoology.) 



