OYSTERS AND DISEASE. 
(Fig. 9). Barfurth and Frenzel have shown the presence of three kinds of cells in the 
glandular epithelium of the inolluscan liver, viz. — " Kornerzellen," " Fermentzellen," and 
" Kalkzellen " ; but not all of these are present in all cases. Frenzel* states in regard 
to the common oyster : — " (a) Die Kornerzellen haben einen Durchmesser von circa 32 
mikr. Die Korner sind gelb- bis rothlich-braun gefarbt, 3 bis 4 mikr. gross und kugelig. 
Die granula sind wenig zahlreich und punktformig. (/;) Ferment- (Keulen-) Zellen 
nicht aufgefunden (Marz). (c) Kalkzellen fehlen." 
We find two kinds of glandular cells in the liver of our oysters — the ordinary 
large granular liver cells (Kornerzellen), and smaller, more deeply-staining cells, which 
we take to be Frenzel's " Fermentzellen." The relative positions, sizes, and appearance 
of these cells is shown in Figs. 6, 7, 8, &c., on PI. III. We have in some cases (Fig. 12) 
observed the presence of small green pigmentf granules in the larger cells, but have 
not found any giving an iron reaction. Here and there, in the vesicular connective 
tissue between the ceeca, may be seen (Fig. 10, e. c/il) the aggregations of dark green 
granules described as " entero-chlorophyll " by MacMunn. Whether this pigment is a 
modification of the yellow hepatochrome described by Miss Newbigin in the liver and 
integument of Crustacea, and which apparently may vary from red to green in colour, 
or is a derivative of chlorophyll from vegetable food, as held by MacMunn, and this 
seems very probable, cannot be determined without further investigation both spectroscopic 
and chemical. In the meantime, enterochrome (see Newbigin, Quart. Journ. Mic. Sci., 
November, 1898) certainly seems the more appropriate name for this pigment, or set 
of pigments. 
* Mikrographie der Mitteldarmdriise (Leber) der Mollusken. Nova Acta Leop.-Carol. Akad., Bd. XLVIIL, 
No. 2, 1886. 
t Kyder also debcribed gieen pigmeiil in ihc inner ends of the liver cells in 1893. 
