DEGLUTITION (S. s. 443) 141 



that the sketch represents the maximum gape, for the effect of chemical 

 fixatives seems to be to lock the jaws tightly rather than leave them agape. 

 When examined alive mononchs are seldom seen to move their mouth 

 parts. 



The Mononch and Its Victim 



Fate of Victim. So far as I am aware, the struggle of a mononch 

 with its victim has never been witnessed by human eyes. A struggle it 

 must be, for mononchs are sometimes discovered that have gulped down 

 other nemas nearly half as long as themselves. Such a denoument must 

 be the result of a dramatic conflict. A similar gastronomic exploit on 

 the part of a man would be the gulping down of a string of bologna sau- 

 sage several feet in length. In one instance in the course of my experi- 

 ence, a mononch was caught with its quarry, another nematode, still 

 gripped in its jaws. Seized by its middle, the victim had been bitten 

 nearly in two. This is a common fate. Sometimes, however, the ingested 

 nema is but little mangled. I imagine the mononch swallows its prey 

 somewhat as the python does, though less deliberately. As the oesophagus 

 seldom occupies over one-fourth of the length of the body, and as the 

 mononch sometimes swallows other nemas nearly half as long as itself, 

 manifestly in such cases one end of the victim's body must reach the 

 mononch's stomach before the other end has disappeared down its 

 throat. 



Gluttonous Appetite. While many mononchs bolt their food, it is 

 evident that the food of some among them receives 

 a certain amount of mastication, for the body of 

 the victim is bitten into fragments and swallowed 

 piece-meal. In some cases the degree of mastica- 

 tion may be greater still. Figure 10, for instance, 

 shows the head of a preserved specimen, in the 

 mouth of which lies a portion of the "gizzard" of a 

 rotifer, which has been almost completely denuded 

 of the muscular tissue originally attached to it. It 

 is the thick-lipped species like M. muscorum that 

 masticate their food in this way. 



(Esophagus or Gullet 



Lining of the Gullet. Salivary (?) Glands. The oesophagus is more 

 or less cylit?droid, a form of oesophagus common in nemas that engorge 

 relatively large objects. The anterior end of the oesophagus, where it 

 receives the base of the pharynx, is usually about one-half to two-thirds as 

 wide as the base of the head, and is occasionally somewhat swollen, so 

 that one may speak with propriety of an obscure pharyngeal bulb. The 

 oesophagus has nearly the same diameter throughout the greater portion of 



