330 DAVID BRYOE ON 



that when the collapse of the tube occurred, this portion was 

 momentarily distended. These more intimate details were being 

 obtained from my second example (whose host, after isolation, 

 I had left in greater freedom and which was steadily feeding all 

 the time), when a movement in the rotifer attracted my eye, 

 and I then glimpsed some particles passing quite rapidly through 

 the distended tube of the parasite. I had scarcely realised what 

 was happening when the particles were ejected into the water 

 outside the rotifer, issuing from the point where I had located 

 the posterior extremity of the parasite. The particles seemed 

 to me, as they floated in the water, to be portions of the granular 

 tissue lying between the two membranes of the wall of the 

 stomach of the rotifer. 



At each side of the head of the parasite I could see an elon- 

 gated body suggesting a gland, with minutely granular contents. 

 These external bodies seemed undoubtedly to belong to the 

 parasite. Their contents seemed to be moved occasionally by 

 some pressure as they changed position. I also observed some 

 slight independent movement in the anterior part of the head 

 of the parasite. As a general rule the head did not change its 

 position, but now and again I saw a slight movement as though 

 it was altering its hold. 



What I could make out of its head will be best understood 

 from fig. 6 h, where it is shown in situ on the exterior of the 

 stomach of its host. It seemed to have an external definable 

 integument, which in front was not continuous, but as though 

 there was there some opening. Within the integument was what 

 I took to be mainly a muscular structure with a small central 

 cavity communicating with the distensible tube behind. The 

 lateral gland-like bodies I have already described. 



I estimated the length of the second parasite as about 300 yu, 

 if straightened out. 



When I examined the host it was evident that, although 

 feeding without cessation, it was not in a normal condition. The 

 last two segments of the central body, known as the lumbar (or 

 preanal and anal) segments, were unusually distended and the 

 organs there located could not be defined. The contractile 

 cloaca, which normally fills and empties itself every minute 

 or so, was not acting at all. The inference was that the 

 parasite was drawing and expelling so much fluid from the 



