NEMATOMORPHA ANATOMY 



I6 7 



is found in the larva, though the two dorsal splits from the walls 



of which the spermatozoa will arise are present. They are lined by 



a definite epithelium (Fig. 83), and this serves at once to distin- 



guish them from the body-cavity. Posteriorly the splits narrow 



and become the two vasa deferentia which open one on each side 



into the cloaca. The cells 



lining the lumen give rise to 



secondary cells, and these be- 



come spermatozoa, the process 



extending from behind for- 



wards. The external organs - 1 



bursa, etc. described by ~h. 



Vejdovsky were not found 



by von Linstow. 



In the female larva two 

 similar splits are present ; 



these form the egg-SaCS. POS- FIQ gg..^^ through a matu re female 

 teriorly they end in two short Gorditis tolosunus. (From von Linstow.) 



oviducts which open into a Lettering " in Fig " 84 ; * < ^ c ; h ' vary ' 

 uterus, in which fertilisation takes place, and in which the secre- 

 tion arises which cements the eggs together. In the adult the 

 ovaries and a receptaculum seminis are found, in addition to the 



organs present in the 

 larva. The ovaries 

 are formed from 

 modifications of the 

 packing tissue ; they 

 begin close behind 

 the head, and soon 

 attain such dimen- 

 sions as to compress 

 the egg -sacs and 

 body-cavity to small 



Pro. 86. Section through a female Gordius Mosanus slits. After a time 



the 



* 



almost empty ; i, dorsal canal containing eggs ; j, re- ovary and the egg- 

 ceptaculuin seminis. 



sorbed, and the eggs grow into the latter. In the old females, 

 where the egg sacs are empty, there is a considerable space round 

 the exhausted ovary, into which eggs continue to fall off; there 



