70 THE EARTHWORM. 



it forms the distal limb of the long loop, both 

 limbs of the short loop, and a portion of the 

 proximal limb of the terminal loop. The duct 

 in this portion of the tube is wide, intracellular, 

 and non-ciliated ; and its walls consist of very 

 granular protoplasm. 

 e. The fourth part of the tube, or 'bladder,' forms 

 part of the proximal, and the whole of the distal 

 limb of the terminal loop. It is much wider than 

 the rest of the tube ; it is lined by epithelium ; 

 and its walls, which are non-glandular, contain 

 interlacing muscular fibres. The ' bladder ' opens 

 to the exterior by the aperture already seen. 

 (See pages 62 and 68.) 



E. The Reproductive System. 



The earthworm is hermaphrodite. The reproductive 

 organs are lodged in segments ix. to xv., i.e. in the region of 

 the oesophagus. 



1. The female organs consist of a pair of ovaries ; a pair of 

 oviducts, with a receptaculum ovorum opening into 

 each ; and two pairs of spermothecae. 



a. The ovaries, which lie in segment xiii.. are a pair 



of small white pyriform bodies attached to the 

 septum forming the anterior wall of the segment, 

 and hanging freely from it into the ccelom below 

 the oesophagus. 



To see the ovaries and oviducts stretch the body-wall 

 transversely and longitiodinally , and look fm- them loith a 

 hand lens. 



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



mouths of which are placed in the hinder part of 

 segment xiii., 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. 



