THE OVAEY AND THE TESTIS. 129 



matter, which are developed in different individuals, 

 termed males and females. 



These two kinds of living matter are ova and sperma- 

 tozoa, and they are developed in special organs, the ovary 

 and the testis. The ovary is lodged in the female ; the 

 testis, in the male. 



The ovary (fig. 30, ov) is a body of a trefoil form, 

 which is situated immediately beneath, or in front of, 

 the heart, between the floor of the pericardial sinus and 

 the alimentary canal. From the ventral face of this 



0(1' 



Fig. 30.— Astacm fluviatilis. — The female reproductive organa ( x 2) ; 

 ov, ovary ; od, oviduct ; od', aperture of oviduct. 



organ two short and wide canals, the oviducts {od), lead 

 down to the bases of the second pair of walking limbs, 

 and terminate in the apertures (od') already noticed 

 there. 



The testis (fig. 31, t) is somewhat similar in form to 

 the ovary, but, the three divisions are much narrower 



