GEi\'hA A L ORGANOLOG Y. 



141 



the epithelial covering of the body cavity, in many animals 

 permanently, in others only temporarily; in the latter 

 case, it separates, usually by constriction, and forms gland- 

 like bodies, the sexual glands. 



Gonochorism and Hermaphroditism. In most ani- 

 mals, the germinal epithelium produces either only female 

 or only male sexual cells; such animals are called separate- 



s to di 



FIG. 63. Sexual organs of Lumbricus agricola. (From Lang, after Vogt and Yung.) The 

 seminal vesicles of the right side are removed. 6i, ventral nerve-cord ; bv and /'/, ventral 

 and lateral rows of setae; si 1 , si y , receptacula seminis; .r^ 1 , si"*, s& 3 , the three seminal 

 vesicles of the left side, which are connected with a median unpaired seminal capsule 

 (s6u). Enclosed in the latter are the anterior and posterior testicles (/;>, // 2 ), and the an- 

 terior and posterior seminal funnels (/*, ^ 2 ), which lead into the vas deferens (v</\. a, 

 ovaries ; to. ciliated funnels leading into the oviducts (ov) ; di, remnants of the dissepi- 

 ments ; VIII-XV, eighth to fifteenth segments. 



scxcd or gonochoristic, in opposition to the hermaphroditic 

 forms, in which both kinds of sexual glands are contained 

 in one and the same individual. Different degrees of her- 

 maphroditism can be distinguished ; commonly testes and 

 ovary are contained in the same animal, yet separated by 

 a space within the body, as, for example, in our anglc- 

 ivonn, in which only a couple of segments are male, while 

 a third segment is female (Fig. 68). More rarely, there is 



