the Syngamus trachealis. 257 



and isolated specks, and by leaving unfilled furrows, which 

 cross each other, and give it the appearance of a vascular net. 



Next to the intestinal canal, the generative organs of this 

 worm are the most striking. In the male is perceived a dirty- 

 white very thin vessel, which begins by an unattached slender 

 extremity near the middle of the oesophagus, and winds itself 

 down the intestine. The vessel becomes larger and larger as it 

 descends; and, with the last bend which it makes at the lower 

 end of the branch, it suddenly contracts and runs down as a 

 very slender canal to the above-mentioned slit. I could not 

 properly follow the end of this canal, as it was very indistinct 

 before the slit, and partly covered by two small long and 

 thin bodies. These long jjodies, which lay in the hinder ex- 

 tremity of the male branch, bent near the slit, consisted of a 

 horny substance, arid touched one another at an acute angle, 

 directed downwards. A fine white granular matter formed 

 the contents of this receptacle. The vessel could easily be 

 taken out entire by cutting off the branch. 



A much more compound vessel, with the intestinal canal, 

 occupied the female branch and the other parts of the body. 

 There were here two vessels with blind ends which began in 

 the lower part of the cavity of the body, ascending the gut as 

 two very thin milk-white canals, with irregular windings and 

 twistings, and forming, chiefly at the beginning of the female 

 branch, several convolutions, one of which reached a great way 

 up the female branch and then returned. On their passage, both 

 receptacles decreased towards the middle of the body for a 

 short space, but soon changed into two thick dirty-white tubes, 

 which in breadth nearly equalled the circumference of the in- 

 testinal canal. Near the end of the gut these tubes bend, and 

 then turn upwards and reach the place where the male and fe- 

 male branches join, after both having formed some few and 

 small windings : here they are united into one vessel, and 

 send a very thin tortuous canal to the above-mentioned slit. 

 From the construction, order, and contents, I supposed this 

 double receptacle to be nothing less than the female generative 

 organs, such as we find in most of the Nematoidea. One could 

 easily distinguish the following parts on it, namely, 1st, The 

 two thin and milk-white vessels, situated in the back part, are 

 certainly the ovaries. They contained in their posterior con- 

 volutions a fine granular white substance; while in the an- 

 terior its granules were more firmly pressed together, and 

 on the ovarium being injured, escape adhering together in 

 a cylindrical form. Nearer to the upper part the granules 

 were clustered together in small heaps, so that the whole 

 matter appeared already to have separated in simple vitelli; 



Third Series, Vol.10. No. 61. April iS 37. 2L 



