1904-5.] ON THE ABSORPTION OF FAT IN THE INTESTINE. 251 
of inorganic salts, probably iron, as Macallum has conclusively shown 
that these cells pick up that element. One can, however, demonstrate that 
they also contain fat. If preparations from animals fed with fat made 
with Flemmings Fluid be placed in ether for twenty-four to thirty-six 
hours, the granules, which before appeared deep black, become colourless, 
having slowly dissolved in the fluid. Further, if the preparation is made 
with ten per cent. formalin for twenty-four to forty-eight hours, and the 
preparations sectioned with freezing microtome and stained with scarlet 
red, for forty-five seconds the fat granules appear bright red. If, how- 
ever, before staining they are placed in ether for twenty seconds the red 
granules disappear, this showing that the cells do take up fat. 
As already pointed out it was Zawarykin who first brought forward 
the view that leucocytes were the sole means by which fat was taken up 
from the intestinal contents. He claimed that after picking up the fat 
they returned to the chyle vessels. Schafer,* while admitting that fat 
droplets are present in the epithelial cells when the amount of fat in the 
chyme is relatively large, holds that the leucocytes are under ordinary 
conditions the only structures capable of taking fat from the lumen of 
the bowel. He says too that ‘‘no fat particles are, as a rule, found between 
the epithelium and the central lacteal, save such as are embedded in 
lymphoid corpuscles.’”’ In the guinea pig at least, and, according to 
Heidenhain, in puppies also, it is a rare thing to find a leucocyte of any 
description either within or between the epithelium. As remarked, the 
large lymphoid cell is the only leucocyte which picks up fat, and I have 
never observed such a cell either within or between the epithelium, nor have 
I ever seen such a cell in the central lacteal. I have on several occasions 
seen a polymorphonuclear leucocyte in the epithelium with fat almost 
surrounding it, yet containing none itself (Fig. 6). More frequently one 
is able to see lymphocytes within the epithelium, but always free from 
fat (Fig. 8). Leucocytes are present in numbers in the epithelium in 
young kittens, but whether they take up fat I cannot say, since I have 
not studied their action in this respect, but even if they do contain fat, 
their number is altogether inadequate to accomplish very much, a fact 
which tells against the view that they transfer fat through the parenchyma 
to the lacteal. Schafer found that in spring frogs, which had been fed fat 
the epithelial cells showed considerable fat, while November frogs showed 
very little fat absorption, and then none was present in the epithelium, 
the whole being taken up by the leucocytes. He concludes from these 
experiments that under ordinary circumstances the leucocytes take up all 
the fat, while the epithelial cells act as storehouses when the fat is in 
* Pfhuger’s Arch. Vol. 37, p. 395, and Inter. Monatschr. fiir Anat. und Hist. Vol. 2, 1885, p. 6. 
