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 be mentioned presently. 



The earthworm possesses two pairs of very minute 

 spermaries attached to the posterior face of the septum 

 between the ninth and tenth, and tenth and eleventh 

 segments respectively (Figs. 82, te, and 86, f). They 

 have a flattened form and their free or distal ends are 

 produced into finger-shaped processes. Behind each 

 spermary, and in the same segment, is a ciliated seminal 

 funnel opening into the coelome and produced backwards 

 through the septum next behind into an efferent duct, the 

 two ducts of either side communicating with a main 

 spermiduct or vas deferens. Each of these extends back- 

 wards 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 

 apparatus 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 coelome 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 coelome ; but 

 in Lumbricus, the two anterior pairs and the posterior 

 pair 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 coelomic cavity in 

 which one pair of spermaries and seminal funnels be- 

 comes enclosed. 



