362 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



gland except that the tunica propria is separated from 

 the cylindrical epithelium by a very thin layer of 

 muscle. 



The ovaries extend from the end of the second seg- 

 ment of the thorax to the end of the seventh, and some- 

 times even into the first segment of the abdomen. The 

 oviducts are a pair of straight wide tubes in the fifth 

 segment, opening on to the inner side of the basal joints 

 of the fifth pair of legs, as noted by Sars (19), and not, as 

 St. George (22) supposed, in the fourth segment. At 

 their lower ends they widen into sac-like dilations. 

 The ovary contains a single row of eggs, which are large 

 and surrounded by a very thick covering of granular 

 yolk, so that they impart a slightly-lobulated appearance 

 to the otherwise cylindrical tube. The wall consists of 

 cylindrical epithelium, with a basement layer of finely 

 granular appearance, surrounded by a thin tunica 

 propria. According to St. George, an ovum is formed by 

 a single epithelial cell increasing in size, its nucleus 

 becoming the germinal vesicle and filling itself with 

 germinal spots. The eggs when fully developed are 

 slightly ovoid in form, about 0'05mm. in diameter, and 

 contain violet and also yellow-brown yolk. Delia Valle 

 (5) states that the female undergoes ecdysis before laying 

 eggs. The latter pass into the brood-pouch formed on the 

 ventral side of the thorax by the four pairs of lamelliform 

 oostegites attached to the first four thoracic legs, and there 

 develop. Delia Yalle has shown that the eggs are passed 

 on into the brood-chamber without an external envelope, 

 and only secrete the vitelline membrane after fertilisa- 

 tion. In confirmation of Leydig, he has proved that in 

 both G. locusta and G. fulex, the cleavage is at first total, 

 sixteen cleavage spheres of equal size being formed, but 

 later appears superficial, the originally distinct cells be- 



