7fi 



Fig. 32/;. Eiiithelium of kidney, x 1,500. 



Fig. 3Sa. A fragment of the ovary in section, x 300. 



Fig. S3b. Section of young ovum, x 600. 



Fig. 34a, /;, c. Diagrams showing the development of sperms 



in the testis (after Gibson), x ca. 350. 

 Figs. 35-42. Figures of the development of Patella (after 

 Patten). Enlarged to various degrees. Fig. 36 

 is a ventral view. Figs. 37—40 are sections. 

 Figs. 41 and 42 are views of the oral (ventral) 

 side of the embryo. An.C. = Anal cells. Ap.D. 

 = Apical disc. Bj). = Blastopore. Cil.B. = Pre- 

 blastoporal ring becoming the prototroch. Ect.^ 

 Ectoderm. E.-M. = Endo-mesoderm. Mcp. = 

 Micropyle. Mew, or F.-R. = Foot rudiments 

 (mesoblastic). Ilesen. = Mesenteron (endoder- 

 mic). Pr.-Tr. =. Prototroch. Beet. = Eectal 

 evagination of midgut. Bad. = Invagination to 

 form the radular sac. • 



C. TiNT.IN 



AND Co., PniNTF.RS, 53, VlCTOItlA Strekt, LlVE::r(10L. 



