vi REPRODUCTIVE ORGANS 347 



Certain globular sacs called spermothecce (Fig. 86) also 

 belong to the female part of the reproductive apparatus. 

 Of these there are usually two pairs (sometimes more than 

 two in Allolobophora) situated in the ninth and tenth 

 segments, and opening to the exterior between the ninth 

 and tenth, and tenth and eleventh segments respectively ; 

 their function will bs mentioned presently. 



The earthworm possesses two pairs of very minute sperm- 

 aries attached to the posterior face of the septum between the 

 ninth and tenth, and tenth and eleventh segments respectively 

 (Figs. 82 te, and 86, t\ They have a flattened form and 

 their free or distal ends are produced into finger-shaped 

 processes. Behind each spermary, and in the same seg- 

 ment, is a ciliated seminal funnel opening into the ccelome 

 and produced backwards through the septum next behind 

 into an efferent duct, the two ducts of either side communi- 

 cating with a main spermiduct or vas deferens. Each of these 

 extends backwards in the ventral body-wall to open by a 

 tumid lip on the fifteenth segment (Fig. 86), near the inner 

 couple of setae. 



The most prominent portions of the reproductive appar- 

 atus are certain large whitish bodies the sperm-sacs or 

 seminal vesicles (Figs. 82, ves. sem, and 86, sp. s\ which are very 

 apparent in the adult worm as soon as the ccelome is cut open 

 in this region. Of these there are three (Lumbricus) or four 

 (Allolobophora) pairs, situated in segments 9 12. They arise 

 as outgrowths of the septa, and communicate with the ccelome; 

 but in Lumbricus, the anterior pair and the two posterior pairs 

 respectively become joined across the middle line so as to 

 form two median sperm-reservoirs (med. ves. sem, and s.s), 

 each of which encloses a ccelomic cavity in which one pair of 

 spermaries and seminal funnels becomes enclosed. 



The cells of which the spermaries are composed do not 



