GASTEROPODA OF THE UNITED STATES. 37 



its duct is as long as the oviduct. The vagina is 

 moderately broad. The cloaca is short. The exte- 

 rior generative orifice is on the right side of the head, 

 considerably posterior to the inferior tentaculse. 



Chapter vii. — general remarks upon the junction 

 OF different portions of the generative appara- 

 tus, AND the structure OF ITS TISSUES. 



The testicle was mistaken by Swammerdam, Cuvier, 

 and others for the ovary, and the latter organ and pros- 

 tate gland for two portions of the testicle. A micro- 

 scopic examination of these different organs at once, 

 very easily settles their true nature ; although, even 

 without this mode of analysis, we would suppose the epi- 

 didymis would indicate the character of the gland of 

 which it is the duct, and leave the remaining two organs 

 to be considered as belonging to the female apparatus. 

 In Helix, the structure of the testicle consists of dense 

 fasciculi of short coecal pouches, which are simple, bifur- 

 cate, or trifurcate. These contain polygonal spermato- 

 phori, which are finely granular with a round nucleus, or 

 filled with granular globules of uniform size, or with coils 

 or bunches or fascicuh of spermatozoa. The epididymis 

 always contains, more or less, and is frequently dis- 

 tended with, a white, silky, filamentous substance, com- 

 posed of spermatozoa. The latter consist of very dehcate 

 and, comparatively, enormously long filaments, terminat- 

 ing, at one extremity, in a thickened head. They vary 



