STUDIES 0?f THE ECTOPARASITIC TREMATODES OE JAtAJf. gl 



the Holostomidac are regarded by Brandes" as having the same 

 function. As to the action of the pharyngeal glands in Tristoinum I 

 am not able to say anything definite ; at any rate I have not observed 

 any inflammation on the gill of the host, so that I believe they are to 

 be regarded merely as mucous glands. 



Next, concerning the salivary glands. These are, in my opinion, 

 clearly to be distinguished from the glands of the same name above 

 referred to in the turbellarians. In EJiabdocoelida, however, there are, 

 as already mentioned, two sorts of salivary glands ; and in this case 

 those that open between the pharynx and the intestine are perhaps 

 analogous to or at any rate a forerunner of the salivary glands of the 

 ectopai'asitic Trematodes, In Distomum Westermani (Kerbert) and 

 Dist. palliatum ( L o o s s ) , there are also true salivary glands opening 

 into the oesophagus. As to the function of these glands I am not in 

 a position to make any assertion; but some light will perhaps be 

 thrown on the question after we have considered the characters' of the 

 intestinal epithelium. 



We have already seen that the intestines may be distinguished 

 into two types according to the character of their epithelium. We 

 shall begin with the first type, tiz., that in which the epithelium is 

 discontinuous, and in which the cells contain numerous dark-brown 

 or almost black granules. The chief question on w^hich I shall venture 

 to make a few remarks is about the nature of these pigment granules. 

 On this point there are, so far as I know, two views. According to 

 Taschenberg'^ these pigment granules ai'e the food-particles taken 

 in by these cells from the cavity of the intestine j and in support of 

 this view he cites his observation that these pigment granules are most 



1). Brandes— Die Familie der Holostomiden. Zoolog. Jahrbucher. Abtheil. f. Syst. Greo. u. 

 Biologie. Bd. 5, 1891. p. 553-561. 



2). Taschenberg— Weitere Beitriige zur Kenntniss eotoparasit. mariner Trematiodeii, 1879. 

 p. 11-12. 



