I'll M.I M \NM IATA 



4G3 



the eapBulogenous glands (p. 457). situated in the neighbourhood 

 of tlir reproductive organs. The sperms from the male apertures 



of each pass along temporarily formed grooves to the teceptaeufa 



semiuis of the other. 



When the ova are mature they are discharged from the ovary 

 into the cavity of the thirteenth segment, whence they pass out 

 to the exterior through the oviducts, to be enclosed in the cocoon 



/TICS 



blast op 



ner- 



Kk ;. WA.— Early stages in the development of Lumbricus. A, lateral view of flattened blastula ; 

 B. ventral view of gastrula with slit-like blastopore ; C; lateral view of later stage. Maxtor. 

 blastocoele ; blastop. blastopore ; ect. ectoderm ; en<l. endoderm ; m. primary mesoderm cell ; 

 mes. mesoderm bands ; ner. cell from which the primitive nerve-cord (ne. co.) takes origin ; 

 npli. cells taking part in the formation of the nephridia ; st. stomodteum. (After Wilson.) 



(vide infra), after having being detained for a time in the 

 receptaculum ovorum. 



Development. — The oosperms or fertilised ova of the Earth- 

 worm are enclosed, together with a quantity of an albuminous fluid 

 derived from the capsulogenous glands, in a cocoon, the wal^"of 

 which is formed of a viscid secretion from the glands of the 

 clitellum, hardened and toughened by exposure to the air. The 



