216 THE GEOUSB IN HEALTH AND IN DISEASE 



upon each side, and the whole cell has the appearance of being built up of two 

 rows of rounded bricks lying side by side in a double pile. The nucleus remains 

 large, oval, and conspicuous. At the end of each cell there is usually a dark 

 granulation which serves very clearly to define their limits. 



The lumen of the oesophagus which pierces these peculiar cells is very minute, 

 and is lined with a definite chitinous tube. The " cellular body," as the aggregate 

 of the cesophageal cells is sometimes called, ends abruptly, about one-fifth the body- 

 length from the anterior end. Here the oesophagus passes quite abruptly into the 

 capacious intestine with its many-celled walls. Just at this point, and tucked 

 away in the angle formed by the minute oesophagus widening into the broad 

 intestine, are a couple of glands, probably the homologues of the cervical glands of 

 other nematodes. The intestine continues to the hinder end of the body with no 

 change ; it is somewhat difficult to distinguish, as it is just about the same brown 

 colour as the lateral lines. The posterior end of the female is truncated, and the 

 anus is at the ventral side of the abruptly terminated body. 



The ovary is a single tube which anteriorly contains undifferentiated eggs. 

 These gradually attain a definite and somewhat irregular outline. Posteriorly the 

 ovary opens into a spacious uterus, in which the ova are oval, with a distinct 

 vitelline membrane. The uterus is broad, and serves, with its contents, to conceal 

 the other organs of the body. Posteriorly, where the body is wide, the ova are 

 irregularly crowded together ; there may be as many as five or six ova in a 

 transverse row. Further, towards the head the ova acquire their characteristic egg- 

 shell with two bright spots at each end. They closely resemble the eggs of 

 Trichocephalus trichiurus (dispar). About halfway along the body the diameter 

 lessens as we pass forward, and after a certain space the uterus is narrowed and 

 only permits a couple of eggs to be abreast, and finally the eggs are reduced to a 

 single row. The uterus opens by a vagina which is situated a little way behind 

 the end of the "cellular body," i.e., just behind the anterior end of the intestine. 

 The uterus or vagina is usually prolapsed and forms a bell-like structure, one edge 

 of which usually has a clear oval vesicle in its walls. Through this bell-shaped 

 structure the eggs pass out. 



The male is markedly smaller than the female. Its average length is about 25 mm. 

 and its width throughout does not surpass the anterior end of the female's body. 



The testis is a single tube which opens posteriorly. At the tail end the male 

 has a pair of cuticular folds or flanges, possibly representing a genital bursa. There 

 is a single spicule, very long, and in many cases only perhaps protruded for a 



