No. 612] GENESIS OF ORGANIZATION OF INSECT EGG 709 



cell to the growth period of the oocytes produced by this primordial 



ends the pole-plasm has become equally distributed aiDoiig the sixty- 

 four oogonia. Then ensues the growth period during which the^ pole- 

 contained in the primordial germ cell of the preceding generation or 

 to that contained in all of the sixty-four oogonia which descended from 

 that primordial germ cell. That is, the pole-plasm of the oocyte under 

 discussion has in some way increased until its mass is sixty-four times 

 as great as that of the oogonium before the growth period began. How 

 this increase has taken place can only be conjectured. The pole-plasm 



by the division of its constituent particles or by the intiuence of its 



'Die influence of a specialized mass of cytoplasm upon 

 llie chromatin is very well illustrated by the inhibition of 

 eliromatin-diminution in j\Ii(h'>for and Ascaris. In M'lastor 

 nuclear division is normal until at the four-cell stage one 

 nucleus reaches the pole-plasm at the posterior end (Fig. 

 12, a, IV.). During the succeeding mitosis this nucleus, 

 which is ai)i)ar(']itly uiuhM- the control of the pole-])las]n, 

 does not uii(h'i-n .-ln'omnl iii-dlmiiiutioii. wlicrca^ the other 

 three do. Oih' ..f iIh- d.-iu-lilci- luu-lri ivMiitiim tV.nn the 

 division (.f thi^ uii.liniiiii^lHMl iinrl..ii^ iviiKiiii^ entirely 

 within tlie pole plaHu ainl i> eiit off from Hie rest of the 

 egg with tlii> -iie('i:ili/.e(l m.'i>> of e\ t(ii il<'i>ni n> the primor- 

 dial gei'ui cell (Kiu-. rj. /-). 'riii> nnelen^ always retains 

 the full amount of cliromalin : hut its sisttM- nucleus, which 

 remains in the egg and is thus separated from the direct 

 influence of the pole-plasm, undergoes diminution at the 

 next mitosis. 



\ siinilnt- seoM-eontimi of sviecializcd evtoi>lnsm m tlie 



