132 TUANSACTIONS AND PKOCEEDINGS OF THE [Sess. lxvi. 



apparent. The formation of the primary germ-cells in the 

 skate — and in all probability in every other Metazoou — 

 corresponds broadly to the genesis of spore-mother-cells on 

 the asexual generation of a plant — the sporophyte. 



:s<3 



SPERMATOGENESIS E.O. 

 PALUDINA. 



Fig. 1. — Diagram of the Life-Cycle of the Skate (Baja hatis). 



With this recognition it becomes possible to compare 



together, so as to show their essential similarity, the 



