PLATE IV. 



MODE 0? ORIGIN CF NEW LIVING CENTRES IN ALREADY EXISTING 

 BIOPLASM. OVA OF TEIE COMMON STICKLKBACK. 



neiit. iii th* initial 01 a delicate tissue coii- 



iiuiing the ovary and composed or ceils. 



he orum s-ems to ari e by the growth of one 



o: these. MaiuiC-d 6'0 diameters. 



Ovarian Drum. wi:h larfift germinal vesicle 

 and uumeroas germinal spots or new centres 

 'I he yoke, a, cracked and nxhihitinft fissures 

 radiating ouLwarc.- :,U$mfied ICO diatneteis 



Germiii.ii. spots from a ruptured germinal vesicle, x C50. The ovum was 5 ' s -Inch in diarnetei, 

 and the gei-rhiual vesic-ie ^\-. 







'ji-rminal spots, witli new centres (micleoli) 



\Mtliin tjjem and more minute germinal spots 



in the intervals between tii^m. x 660 



Extremely minute germinal spots, with new 

 centres originating within th^m X 1700 



of an inch x : >]5. 



x 1,700. 



To face 



