Harqitt: Pennaria tiarella and Tubularia crocea. 



PLATE 5. 



Tiihularia crocea. 

 All eggs killed in corrosive-acetic. All Figures X 1600. 



Fig. 30. Oocyte before growth; chromatin has begun to form a thread. 

 Iron hematoxylin. 



Figs. 31-33. Oocytes in synapsis stage; loops of spireme in a polar arrange- 

 ment. Iron hematoxylin. 



Fig. 34. Two oocytes; a, oocyte not growing, with chromatin in scattered 

 masses; h, oocyte with loops still present but becoming granular; 

 polar arrangement lost. Iron hematoxylin and Congo red. 



Figs. 35-37. Oocytes at the start of the growth period. Spireme of nucleus 

 has lost its polar arrangement. Iron hematoxylin. 



Fig. 38. Oocyte at the beginning of growth, with the chromatin in delicate 

 granular strands. The double appearance of the threads may be 

 accidental. Iron hematoxylin. 



Figs. 39-47. Germinative vesicles of growing oocytes of various ages show- 

 ing stages in the disappearance of the nucleolus. 



Figs. 39, 40. Substance has left the nucleolus and is collected in several 

 places in the nuclear reticulum. In Figure 40, a is the nucleus 

 of an oocyte which would probably have served as food; nucleolus 

 larger than that of the growing egg, h. Picro-hematoxylin. 



Fig. 41. Nucleolar fragments in nuclear reticulum. Ehrlich's hematoxylin 

 and eosin. 



Fig. 42. Oocyte about one-quarter of its mature size; nucleolus in several 

 pieces. Picro-hematoxylin. 



Fig. 43. Oocyte about half grown; nucleolus in several pieces. Ehrlich's 

 hematoxylin and eosin. 



Fig. 44. Oocyte nearly full grown (entire egg shown in Figure 56) , nucleolus 

 in one large vacuolated, and several smaller fragments. Ehrlich's 

 hematoxylin and eosin. 



