324 J- Beard, The Sexual Conditions of Myzostoma glabrum (F. S. L.). 



Fig. 7, A similar section from a young disc-form (tab. 2 no. 1) showiug regulär 

 ccelomic eplthelium with eggs. Zeiss obj. F. oc. 2. = 500 diam. 



Fig. 8. From the same animai. Showing two eggs [o.c] in the ccelomic epl- 

 thelium. Zeiss obj. F. oc. 2. = 500 diam. 



Fig. 9. A section of a bit of the ccelomic epithelium with egg-cells. From a 

 young disc-form (tab. 2 no. 5). Zeiss obj. F. oc. 2. = 500 diam. 



Fig. 10. Section of body-wall and ccelomic epithelium of a young disc-form 

 (tab. 2 no. 1). Zeiss obj. F. oc. 2. = 500 diam. 



Fig. 11. Section of a much smaller male (tab. 1 no. 2) showing further stages in 

 the development of spermatozoa. Zeiss obj. F. oc. 2. = 500 diam. 



Fig. 12. Section of a male (tab. 1 no. 1). The development of male Clements 

 from the dorsal ccelomic epithelium has proceeded apace. There is no 

 trace of a regulär epithelium, or of ovarian cells. Comparison of this 

 figure with figs. 1 — 5 demonstrates very clearly the differences, referred 

 to in the text, between the dorsal ccelomic epithelium of male and of 

 hermaphrodite specimens. Zeiss obj. D. oc. 2. = 225 diam. 



Fig. 13. Section of a male (tab. 1 no. 6). In this case the regulär ccelomic 

 epithelium is becoming converted into sperm-mother-cells [sp.c]. Zeiss 

 obj. F. oc. 2. = 500 diam. 



Fig. 14. Nansen's Organs from a young disc-form (tab. 2 uo. 5). Leitz obj. 7 

 oc. 2. 



Fig. 15. Stages in the development of spermatozoa from a section of the lateral 

 portion of the body below the alimentary cceca. From a large male 

 (tab. 1 no. 9). In this specimen the cells of Nansen's ovary agree in 

 all respects with the sperm-mother-cells here depicted. Leitz obj. 7 oc. 2. 



Fig. 16. Transverse section of a young specimen of M. cirriferum, to show the 

 ccelom [co). Zeiss obj. D. oc. 2. = 225 diam. 



