Uoyal Microscopical Society. 57 



Ascaris," altliough Cloquet has correctly described the longitudinal 

 layer of muscles. Similar bands occur in Mermis, Gordius, — and 

 indeed, in all probability, in all Nematoids, as well as in Echino- 

 rhynchus, &c. 



On careful examination it will be at once seen that two of these 

 lines are much broader and more conspicuous than the others : these 

 are lateral in position. The narrower hnes are dorsal and ventral, 

 the ventral hne in the female deviating from its course and passing 

 on one side of the sexual orifice, not dividing and surrounding it, 

 as is stated by Cloquet. 



The alimentary canal behind the pharynx in the anterior por- 

 tion of the body is stretched across from one of these lateral bands 

 to the other, but in its posterior two-thirds it is merely suspended 

 in the body cavity and surrounded by the convolutions of the ova- 

 ries in the female, and of the testis in the male. 



This condition of the anterior portion of the ahmentary canal is 

 of considerable importance when viewed in relation to the condition 

 of the bands and alimentary canal in Mermis. In Ascaris I have 

 failed to trace any nearer connection between the ahmentary canal 

 and the lateral bands than, that the ahmentary canal is connected 

 with the body walls at these points by connective tissue of extreme 

 tenuity. I am inclined to the belief that the whole body cavity is 

 lined with an extremely thin membrane which is reflected upon 

 the intestine at these points. It will be necessary hereafter to 

 refer again to this relation of the lateral bands and ahmentary 

 canal. 



The anus is situated at the posterior extremity of the body, 

 and the alimentary canal is usually filled with dark-coloured chyle. 



In these preparations* the whole interior of the body cavity will 

 be seen to be covered with white villi-like processes ; these are the 

 appendices nouricieres of Cloquet, and when examined with the 

 microscope are seen to be pyriform vesicles, which are filled with a 

 white molecular fluid. They are supported by ducts which form a 

 complicated network over the whole inner surface of the body wall. 

 If a transverse section of the worm be made, this network of tubes 

 may be seen to be connected more closely with the body wall at 

 four points than elsewhere ; that is, they are connected with the 

 four longitudinal bands above described. 



The dorsal and ventral bands appear to be the main trunks of 



this system, and to give ofi" lateral branches at short intervals, 



which support the vesicles themselves. Plate LXXVI., Fig. 2, 



represents a portion of one of these trunks with its lateral ducts 



and vesicles. A section of the worm is accurately represented in 



Schneider's ' Monograph on Nematoids.' 



* The preparations here referred to have been presented by the writer to the 

 Museum of the Koyal College of Surgeons. 



