366 WILLIAMS : ON THE GONADS OF THE LIMN^A. 



discoverer, the Swanimerdamian vesicle. This vesicle is a yellow- 

 ish spherical sac lying transversely in the coelom, and situated 

 to the left of the prostata and on a plane slightly inferior to the 

 one occupied by that organ. The proximal portion runs from 

 the pole of the right hemisphere of the sac, crosses over the 

 posterior and upper portion of the base of the prostata, and then 

 running in the groove previously described on the postero-dorsal 

 surface of the penis, it descends by the right side of that organ 

 to unite with the oviduct, and thus form the vagina. (The 

 spermatheca is in reality, a caecal diverticulum of the vagina). 

 The albuminiparous gland -is a linguiform body flexed trans- 

 versely across the convex upper surface of the middle third of 

 the second accessory gland, and firmly bound down to it by 

 peritoneal connective tissue, so that its base looks towards the 

 left, and its apex towards the right. The accessory albuminiparous 

 glands are generally two in number — named first and second 

 according to their position from before backwards, — the first 

 being much larger than the second. They are yellow pulviniform 

 bosses situated along the course of the oviduct, and directly 

 beneath the muscular floor of the pallial cavity, separated from 

 the prostata by a well defined diaphragm consisting of connective 

 tissue, containing muscle cells, and placed hoemally to the 

 receptaculum seminis, oesophagus, stomach, and common 

 generative duct. The posterior third of the second one lies 

 imbedded in the substance of the " Mitteldarmdriise of Frenzel." 

 Both the albuminiparous gland, and its accessory glands swell 

 up so much on the addition of water, that dissection under 

 water is carried on with difficulty, a condition of things that 

 can be remedied by replacing the water with spirit. The 

 hermaphrodite gland (pvotestis) consists of an agglomeration of 

 follicles situated in the "Mitteldarmdriise." In it the spermatozoa 

 and ova are produced from exactly the same kind of germinal 

 epithelium;* these are carried down by the hermaphrodite 



* Reproduction consists essentially in the metazoa of the fusion of a 

 flagellate cell (spermatozoon) with an amoeboid cell (ovum). Both these 



J.C, v., Oct., 1888. 



