No. I.] SPHYRANURA OSLERL 



35 



appear quickly in those nuclei which are subjected to the action 

 of alkaline or neutral fluids, and that it is easily preserved when 

 the fluid is acid. This evidently points out that the intestinal 

 fluid in Sphyranura is acid, the acidity preserving the form of 

 the chromatin of the nuclei, even when the latter are broken 

 down. 



Now, the chromatin portions of the nuclei, if they are swallowed 

 by the intestinal cells, ought to give the latter an intense red 

 hue when stained with alum-cochineal. Instead of that they are 

 very lightly stained, and the staining is a diffuse one, not local- 

 ized towards the free borders of the cell. On the other hand, 

 the free chromatin granules become welded into large masses of 

 amoeboid form and of a gelatinous consistency, and float about 

 in the intestinal fluid, appearing in stained preparations, very 

 deeply colored. They assume various amcEboid shapes pas- 

 sively, owing to the contraction of the intestinal walls, and con- 

 tain, at times, several epithelial nuclei and even epithelial cells, 

 besides a number of vacuoles. They measure variously up 

 to 120 fi. We at first considered these structures to be true 

 Amcebae, but careful observations on them after they were 

 ejected from the intestine showed that they exhibit no vital 

 phenomena, and it was then seen that they were agglomerated 

 masses of nuclein or chromatin. 



From all these facts, — the gradual disintegration of the epithe- 

 lial cells of the host, their final solution, leaving the nuclear 

 chromatin and the agglomeration of the latter into amoeboid 

 masses in the intestine, with the fact that the intestinal epithe- 

 lium swallows but few, if any, of the granular contents, — one is 

 led to conclude that the greater part of the digestive process in 

 Sphyranura is accomplished by a soluble ferment diffused in the 

 fluid contents of the intestine, and, further, that the reaction 

 of these contents, as pointed out above, is acid. 



Frequently the cells of the intestine show, in their outer 

 halves, traces of pigment, which we supposed at first to be 

 swallowed by the cell. It is possible, however, that these pig- 

 ment granules arise from the metabohc processes of the cells 

 themselves. 



As to the origin of the soluble ferment the conclusion at once 

 is that it is derived from the cells of the intestinal epithelium. 

 Reference has already been made above to granules in the 



