6â 



s. GOTO. 



abundant '^N'hen the intestine contains numerous fat-globules, 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 Z el 1er", 

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

 abo-äno-io-en werden durch iuuo^e ersetzt, welche zwischen jenen sich 

 bilden. Offenbar stehen die^^e Zellen in ganz bestimmter Beziehung 

 zur Verdauung." 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 l)e 

 entirely fluid. In my paper on Diplozoo)r\ I followed Ta sehen - 

 ber<T ; Ijut further observations and especially a careful comparison of 

 these pigment granules with the granules found in the e])ithelial cells 

 oîMonocotijlc have convinced me that the two are not of the same njiture. 

 It is, moreover, difficult to understand hy what means digestion is 

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

 for in these, sali^'ary gla.nds, or any other glands which may be 

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

 unicellular glands around tlie oesophagus described by Zeller in 

 Vohjsiomum intcgcrriinnm are, I believe, analogous to the pharyngeal 

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

 some specimens of (hicliocotijlö killed with hot sublimate shortly after 

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

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

 in gr(jups 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 liave been torn away from the tunica propria. It is 



1). Zeller— Weicerer Beitra<j z, Kenutn. d. Pulystomen. Zeitschr. f. wiss. Zoolog. Bd. 27 

 1876. p. 241. 



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



