268 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Fig. 32b. Epithelium of kidney. x 1,500. 



Fig. 33ft. A fragment of the ovary in section, x 300. 



Fig. 33b. Section of young ovum. x GOO. 



Fig. 34a, b, 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. Ay).D. 

 — Apical disc. Bp. — Blastopore. Cil.B. — Pre- 

 hlastoporal ring becoming the prototroch. Ect.~ 

 Ectoderm E.-M. = Endo-mesoderm. Mcj). = 

 Micropyle. Meso, or F.-B. = Foot rudiments 

 (mesoblastic). Mesen. = Mesenteron (endoder- 

 mic). Pr.-Tr. — Prototroch. licet. = Rectal 

 evagination of midgut. Bad. = Invagination to 

 form the radular sac. 



