316 N. M. Stevens. 



Figs. 57 and 58. Resting nuclei of oogonia, showing granules under the nuclear 

 membrane. 2 mm. -12. 



Fig. 59. Young oocyte, showing masses of chromatin-like material at the two 

 ends of the nucleus. 1.5 mm.-12. 



Figs. 60-62. Later stages with several chromatin-like masses inside the nu- 

 clear membrane. 1.5 mm. -12. 



Fig. 63. Young oocyte, showing beginning of network. 2 mm. -4. 



Figs. 64 and 65. Tangential sections of nuclei of S. bip. showing characteri- tic 

 network. 1.5 mm. -4. 



Fig. 66 a and b. Tangential and median sections of nuclei of half-grown oocytes 

 of S. bip. 2 mm. -4. 



Fig. 67 a and b. Similar sections of older oocytes, network disappearing. 2 

 mm. 4. 



Fig. 68. Section of nucleus of nearly mature oocyte of S. bip. No granules 

 or network. 2mm. -4. 



Figs. 69 and 70. Sections of nuclei of S. min. showing amoeboid figures inside 

 the nuclear membrane. 1.5 mm. -4. 



Figs. 71 and 72. Tangential sections of nucleus of older oocytes of S. min. 1.5 

 mm. -4. 



Figs. 73 and 74. Tangential sections of nuclei of oocytes of S. inflata. 1.5 mm.-4. 



