344, EDITH M, PRATT. 
fed zooids with similar sections of starved zooids, a con- 
siderable amount of histological difference was observed 
(figs. 9—11). 
The filaments of starved zooids were densely crowded with 
gland cells containing numerous rounded granules, which 
became so intensely black on staining with iron brazilin and 
iron hematoxylin, that their histological structure could only 
be observed in very thin sections (83—5 mw). LHach gland cell 
was then seen to contain a deeply-seated nucleus and a 
delicate reticulum of protoplasm, in which the granules are 
imbedded. ‘The gland cells near the surface of the filament 
usually contain more granules than the younger more deeply- 
seated cells (fig. 10). It is worthy of note that the granules 
and ingested food matter have not been observed together in 
the same cell. 
Gland cells identical in structure, and, doubtless, also in 
function, have also been observed in the stomodzeum and 
mouth disc. 
A few mucous cells are interspersed between the granular 
gland cells and amceboid endoderm cells. 
Sections from 15—20 yw in thickness were cut through the 
filaments, distended with carmined fish food (fig. 4), and 
microscopically examined without staining. ‘he food was 
observed to be ingested in an amceboid manner by the endo- 
derm cells covering the filaments (fig. 9). Particles of food 
were observed in the act of ingestion (f. f.), and particles of 
waste matter were also seen to be extruded from the cells 
(f. w.). 
Within the cells the food material quickly became enve- 
loped in food vacuoles, and speedily disintegrated; the red 
colour disappeared, and the process of digestion was appa- 
rently completed. 
Similar sections were also stained with iron brazilinvand 
examined in the same way. These were found to contain 
numerous gland cells, which were either empty or contained 
only a few granules (fig. 11). 
From the feeding experiments the following facts are 
