00 



are cells of the germinal wall, which sink below the 

 general epithelium, and then protrude into the ovary, 

 pushing the wall before them until they are completely 

 surrounded by an epithelial layer, several cells thick. 

 The egg itself becomes surrounded by a special nourishing 

 or follicular layer, at the expense of the surrounding cells. 

 With the growth of the ovum, this layer becomes actually 

 folded into the egg substance (PI. IX, fig. Cub. foil.), to 

 increase its surface of contact with the ovum. Further 

 protrusion and folding of the germinal wall gives rise to 

 the characteristic racemes (PL Y, fig. 41, egg. R-). 

 Finally the follicle secretes the chorion round the mature 

 ovum, which now escapes, bursting through the covering 

 layers (fig. Q7b, C. T.), and then passing out by the 

 oviduct. 



Fig. VII. 



Fig. VII.— C. 



■pen. 



V.Etf. 



"N t 



Fig. VII. — Male reproductive organs of young E. aldrovandi. A, fr 

 ventral side ; B, genital duct as in situ, dorsal view; C, genital duct unravel 

 to show various regions ; x 2. 



oni 

 unravelled 



II. Male. 



It is not proposed to give a detailed account of the 

 male genital organs of Eledone, as no male specimen of 

 I''., cirrosa could be obtained. However, the following 

 description of an immature male E. aldrovandi will 



