31 



Univprsity, 



DEVEL0PME:;T of the CVAPJAri EGG. 



The ova develo- in the ectodermal layer of the Tianu- 

 brdum. The erithelium becoites very ruoh thickened i^ four 

 regions; these enlarf^ed areas for- the ovaries. The oriin- 

 itive ovarian cells when first differentiated are larger 

 than the ectoderiral cells of other -oarts. Their nrotcplasm 

 beccn-.es hoirogeneous and of a finely granular character. 

 The nuclei are less hyaline in aDnearaiice j and the nucleo- 

 lus stains deenly. The -ri-itive ova are first distinguish- 

 ed fro": the rest of the ovarian cells by the increase in the 

 density of the cytoplasm and the enlarging of the nucleus. 

 The latter becoiies very large in nronortion to the size of the 

 cell; and acquire.: a vescicular character. The nucleolus is 

 cons"icuous, and a network of chromatin is scattered through 

 the ger-inal vesicle. 



The nri'itive ova gro^.v by the absorntior of the ovarian 

 cells around the-. As gro;vth takes nlace there is a change 



