SPERMATOGENESIS IN PHILOSAMIA CYNTHIA. 



IO3 



to attachment. The other chromatin elements in this nucleus 

 are all irregular and feathery in outline, as in Fig. 18. Fig 19, g, 

 h, is an end view of the same stage, showing a larger structure, 

 with the same characteristic chromatin mass. In? and/ this has 

 become attached to the plasmosome. From the broken chro- 

 matin rods the rings are formed, apparently by a bending around 

 of the rods ; but the exact manner of the change seems very dif- 



39 





Figs. 36-42. Second SpermatocyteDivision. 



Figs. 36, 37. Polar views of metaphase groups with 13 chromosomes. 



Fig. 38. Anaphase. 



Fig. 39. Polar view of telophase. 



Figs. 40, 41. Late anaphase groups, side view, showing 13 chromosomes. 



Fig. 42. Telophase (not all the chromosomes appear). 



ficult to determine (Figs. 20, 21). In this stage, which lasts 

 throughout the winter, the double nucleolus with its chromatin 

 band, is a constant factor. The rings are irregular in size and 



