6^ S. GOTO. 



abundant when the intestine contains numerous fat-jjlobules, and 

 vice versa, which would not be the case were these granules emptied 

 into the intestinal cavity. The other view regards these granules as 

 zymogenic in nature. This view is probably represented by Zeller'\ 

 who says, " Die Zellen losen sich mit der Zeit ab und zerfallen. Die 

 abgtingigen werden durch junge ersetzt, welche zwischen jenen sich 

 bilden. Offenbar stehen die«!e Zellen in ganz bestimmter Beziehung 

 zur Vei'dauung." A third view is possible, according to which these 

 pigment granules are the indigestible remnants of the food taken in by 

 the cells, whether the food be in the form of granules or whether it be 

 entirely fluid. In my paper on Diplozoon-\ I followed Taschen- 

 berg ; but further observations and especially a careful comparison of 

 these pignient granules with the gi-anules found in the epithelial cells 

 of MonocoUjh have convinced me that the two are not of the same nature. 

 It is, moreover, difl&cult to understand by what means digestion is 

 carried on in those forms which have the intestine of the first type ; 

 for in these, salivary glands, or any other glands which may be 

 supposed to have a digestive function, are totally wanting. The 

 unicellular glands around the oesophagus described by Zeller in 

 Polystommn integeiriinmn are, I believe, analogous to the pharyngeal 

 glands of Tristomum ; at least they open at a similar place. Again, in 

 some specimens of Onchocotyh killed with hot sublimate shortly after 

 being detached from the host, I have often observed, in sections, the 

 pigment granules in question in the cavity of the intestine, sometimes 

 in groups and imbedded together in a weakly stained mass. In these 

 cases it is difficult to conceive any external force by which the intes- 

 tinal cells might have been torn away from the tunica propria. It is 



1). Zeller — Weiterer Beitrag a, Kenntn. d. Polystomen. Zeitsohr. f. wiss. Zoolog. Bd. 27 

 1876. p. 241. 



2). This Journal, Vol. IV, Vt. I. p. 174. 



