PORTER: TRICHOXYMPHA. 51 



become surrounded by a deep fold of the posterior part of the body. 

 The most of the cilia are probably afterwards withdrawn from the fold, 

 but the lips of the fold become so closely applied to each other (Fig. li), 

 that the ligneous particles are left behind in the depths of the fold. I 

 believe that the lips of the fold afterwards fuse together, that the walls 

 of the infolded portion then disappear, and that the food thus finally 

 becomes entirely enclosed iu the body protoplasm of the parasite. The 

 condition of the body wall at a in Figure 14 seems to indicate that the 

 wall is there in process of disintegration or dissolution. 



This is certainly a remarkable method of feeding for a ciliate infu- 

 sorian ; but I see no escape from the conclusion that solid food material 

 never enters the animal in any part of the anterior nucleus-containing 

 portion of the body ; for of the hundreds of specimens that I have ex- 

 amined, both living and dead, none have ever shown solid particles of 

 food in the anterior region, whereas the absence of ligneous matter fi'om 

 the posterior part of the body is a condition rarely met with. It seems 

 highly improbable — to say nothing of the absence of any trace of a 

 permanent oral structure — that solid food should pass through this 

 auterior region so quickly that not a single case of its passage, or of its 

 presence in this part, should have been discovered by any one of those 

 who have studied these parasites.-^ But besides this, it is to be noted 

 that the wall of the whole posterior part of the body is thin and ex- 

 ceedingly delicate, so that it would not present any great barrier to 

 the entrance of foreign particles. It disintegrates so readily that I 

 have seen this portion of a living animal go to pieces completely and 

 disappear, while the anterior half, bearing the cilia, continued to swim 

 around. 



For the sake of convenience in description, I shall recognize in Tricho- 

 nympha three regions (compare Plate 2, Figs. 13, 15, 7) : first, an ante- 

 rior nipple-like part, which is quite sharply separated from the following 

 region ; secondly, the middle or bell-shaped part, the axial hinder por- 



1 It is true that Kent speaks of seeing the "pharynx" and digestive cavity 

 densely packed witli milk corpuscles ; but while this Is the case in the posterior 

 portion of the body, I have never seen milk globules or other particles of food in 

 any part of the organism that could be likened to a pharynx. 



Frenzel ('91) likewise was unable to find direct evidence of the existence of a 

 mouth opening in Leidyonella. Althoueh he inclined to the opinion that it was 

 located at the anterior end of the elongated neck-like region, he admitted the possi- 

 bility that it might be located elsewliere. Grassi ('85), too, was equally unsuccess- 

 lul in locating the mouth in Joenia, although in this genus likewise the presence of 

 particles of woody fibre in the body shows that solid food is taken in. 



