1904-5]. ON THE ABSORPTION OF FAT IN THE INTESTINE. 247 
they are not present. That there are lymph spaces, however, | feel cer-. 
tain, and there is quite conclusive evidence to show that the spaces between 
the epithelial cells of at least their basal thirds, are in direct communica- 
tion with these intraparenchymatous lymph spaces, because one can 
frequently demonstrate streams of fat going direct from these spaces 
in the epithelium to the wall of the lacteal. (Figs 2, 5, and 8). 
IV.—FatT IN THE EPITHELIUM. 
That the fat enters the villus directly through the epithelial cells can 
no longer be questioned. When a guinea pig is fed on fat containing food 
for a day or two and killed about four or five hours after the last feeding, 
and the preparations stained as above outlined, the picture is conclusive. 
Fat droplets of various sizes are seen throughout the cells. Although 
there is no uniformity regarding the size of these drops the largest are 
usually seen towards the distal (free) end, (Figs. 1 and 14). Above the 
level of the nuclei the fat is often intercellular, (Fig. 7). At the level 
of the nuclei and below them it may be intracellular (Figs. 4 and 9), or 
intercellular (Fig. 5), but below the nuclei most of the fat is between the 
cells. I do not wish to convey the idea that the nuclear zone 
is a hard and fast line of demarcation, but there is a difference in the dis- 
tribution of the fat in the cell above and below it. I am aware that 
Heidenhain claims that the fat only goes into these intercellular spaces 
when in excess. Von Basch holds that it is present only in a sort of back- 
wash. The former explains its presence between the cells by the con- 
traction due to the fixing agent, whereby the fat is squeezed out of the 
parenchyma into the intercellular spaces. This one cannot accept, for 
preparations from frogs fed with olive oil for a day or two and killed 
about three hours after the last feeding are decisive. The intestines of 
these fixed with ro per cent. formalin for twenty-four to forty-eight hours, 
sectioned on the freezing microtome and the sections stained in scarlet 
red and mounted in glycerine show these intercellular spaces to be filled 
with fat. If, however, before they were treated with the fat stain they 
were placed in ether for about half a minute, these spaces which before 
were red are now light, the fat having dissolved out. If one saw fat in 
these spaces only in shrunken sections Heidenhain’s explanation would 
appear the more probable one, but it is such a constant feature in well 
preserved sections that one must endeavour to account for it in some other 
manner. I believe therefore, that the fat is to a large extent excreted 
by the cell activity into these intercellular spaces. Watney believes that 
the fat is taken up wholly between the cells. Against this may be placed 
