Chap. XIV.] THE EARTHWORM. 287 



septum, between the twelfth and thirteenth segments. The ova 

 increase in size from the attached to the free portion of the 

 organ. The oviducts (ovd.) open by ciliated funnels into the 

 thirteenth segment, pass through the septum between the 

 thirteenth and fourteenth segments, and open on to the exterior 

 on the latter segment near the exterior row of setae. Connected 

 with the funnel of each oviduct is a small sac-like receptaculum 

 ovorum. 



Between the ninth and tenth, and tenth and eleventh segments 

 are the spermathecce or copulatory pouches, white spherical bodies 

 which are accessory female organs. 



The Male Organs. The state of the male organs differs very 

 much in mature and immature worms. The student should not 

 fail to dissect both. 



Fig. 84, B., shows the organs in a young worm in which the 

 cingulum was not swollen. There are two pairs of spermaries 

 or testes (ts. i. and ii.), minute and difficult to see, attached 

 to the posterior face of the septa between the ninth and 

 tenth, and tenth and eleventh segments. In the tenth and 

 eleventh segments are seen two pairs of rosette-like funnels 

 (r. i. and ii.), which form the internal openings of the vasa, 

 deferentia. The two vasa deferentia of each side unite into a 

 common vas deferens (c. v. d.\ which opens by the male genital 

 pore (m. g. p.) in the fifteenth segment. In addition to the 

 essential organs and their ducts there are important accessory 

 organs. These are the seminal reservoirs or vesiculce seminales. 

 In the young worm there are three pairs. The anterior (v. s. i.) 

 grow forwards into the ninth segment. The mid-pair (v. s. ii.) 

 grow into the tenth and eleventh segments from the septum 

 that divides them. The posterior (v. s. iii.) grow backward into 

 the twelfth segment. 



So much for the young worm. In the worm that is sexually 

 mature the vesiculse seminales increase enormously, and form 

 the large-lobed organs shown in 84, A., v. s. The anterior pair 

 and the mid pair unite in such a way as to form a central body 

 which envelopes the anterior testes and rosettes, and which has 

 two anterior and two posterior lobes. The posterior pair also 



