248 TRANSACTIONS OF THE CANADIAN INSTITUTE. [Vou. VIII. 
the fact that in properly prepared sections the most striking thing in 
the field is the great amount of fat inside the epithelial cells. 
Bruyne claims that there is connective tissue between the epithelial 
cells, containing lymphatics so that leucocytes can penetrate between 
the cells and pick up fat from the intestinal contents. He is of the opinion 
that all the fat lying between the cells has been deposited there by these 
leucocytes. So constantly have I found the fat between the cells that I 
cannot accept this explanation. If leucocytes are instrumental in placing 
the fat there one would expect to see them in abundance between the 
epithelium, but in the guinea pig at least their occurrence there isa rarity. 
Not uncommonly one sees more or less irregular circular spaces just 
beneath the striated border which are clear and free. They are found 
after treatment with 10 per cent. formalin, saturated bichloride of mer- 
cury, or absolute alcohol, and even with Flemming Fluid if the osmic acid 
is not of the usual strength. They are due to fat globules having dis- 
solved out leaving vacuoles behind. In somé caseg one can see these spaces 
containing just a small amount of fat, in others a7 spaces are filled while 
the next cell has a vacuole, (Fig. 8). Adjacent cells do not necessarily 
take up an equal amount of fat. Very frequently one sees several adja- 
cent cells loaded with fat while others near them are free from it. 
The nuclei of the epithelial cells never contain fat. It is true that a 
section will at times apparently show fat in the nucleus, but it is due to 
the way in which the section is cut, the fat in the cytoplasm then appearing 
under or above the nucleus. 
Concerning the presence of fat in the striated border special reference 
is made below. 
V.—FAT IN THE PARENCHYMA. 
When a guinea pig is fed fat in excess the adenoid tissue of the villus 
is black with it. (Figs. 2 and 12). It lies in the spaces between the 
leucocytes and the fat streams communicate freely in all directions. In 
some instances, especially when the fat is not abundant, minute drops of 
fat are visible and these frequently present the appearance of a row of 
minute beads, the series being directed generally toward the lacteal. (Fig. 
8). In others the droplets have coalesced into large masses of fat, which 
take the shape of the spaces through which the fat is passing, (Fig. 5). 
It is frequently possible to trace these fat streams proceeding directly 
from the basal end of the epithelial cells, (Fig. 8), but much more com- 
