66 THE EARTHWORM 



forming the anterior wall of the segment, and 

 hanging freely from it into the ccelom. 

 To see the ovaries, carefully cut across the oesophagus in 



this segment, and gently press apart the septa bounding it in 



front and behind. 



b. The oviducts are a pair of short tubes, the wide 



mouths of which are placed in the hinder part of 

 segment xin., one opposite each ovary. 



From the points where they perforate the 

 septum, the oviducts run outwards and slightly 

 backwards to their external openings on the 

 ventral surface of segment xiv. 

 To see tliem, cut through the oesophagus in segment xiv. 



c. The receptaeula ovorum are a pair of reniform sacs, 



attached to the anterior wall of segment xiv. just 

 above the oviducts, into the upper part of the 

 funnel-like mouths of which they open. 



d. TJ spermathecae or receptaeula seminis are two 



mirs of globular sacs lying in the hinder part of 

 sewments ix. and x. respectively. Their ducts, 

 wllich are short, run backwards and open to 

 the exterior in the grooves between the ninth 

 and tenth, and the tenth and eleventh segments 

 respectively, just within the line of the outer 

 double row of seise. 



In these the seminal fluid received from 

 another worm is stored, and from them it is 

 poured out into the egg-case or cocoon in which 

 the eggs are laid. 



Some species of earthworm have the sperma- 

 thecae in segments x. and xi., their ducts passing 

 forwards to open in the same position as above. 



2. The male organs consist of two pairs of testes ;, two pairs 

 of seminal funnels, leading into a pair of vasa defer- 

 entia ; and median and lateral vesiculae seminales. 



a. The vesiculae seminales vary greatly in form and 

 size with the season of the year. When fully 



