450 CHEMISTR Y OF THE DIGESTIVE PROCESSES. 
plasmic processes from the epithelial cells, and one or two l fancied they 
had discovered such appearances, but their observations have not been 
confirmed, and are undoubtedly erroneous. If the epithelial cells of the 
intestine possessed the power of absorbing in bulk fat granules, there 
is no obvious reason why other food particles, such as granules of 
starch or proteid, should not be similarly absorbed, but no such 
absorption has ever been observed, nor are they capable of absorbing 
finely subdivided granules of coloured matter, such as carmine. 
The mucous membrane of the intestine contains an immense 
number of lymph corpuscles. 2 These are found not only in the lymph- 
oid nodules, which occur so abundantly as solitary glands and Peyer's 
patches, but in the intestinal villi, even between the epithelial cells, where 
they may approach quite close to the free surface, and abundantly in the 
adeni rid tissue underlying them. Xow, such lymph corpuscles are capable 
of enveloping and so absorbing fat granules, and have been credited with 
an important function in the removal of fat from the intestine by so 
doing. It was stated by Zawarykin 3 that when fat absorption is going 
on, fat granules are to be found only in these lymphoid cells and not in 
the cells of the columnar epithelium. This statement is undoubtedly 
erroneous, for it is easy, from an animal killed after a meal rich in fats, 
to obtain sections showing the columnar cells filled with fat globules. 
" During active fat absorption, especially if the amount of fat in the 
chyme is relatively large, the columnar epithelial cells become filled 
with globules of fatty matter. These globules are of variable size, and 
may occur in all parts of the cell, but they are generally largest in the 
part between the nucleus and the thickened border, and are often quite 
small near the attached end of the cell." 4 
It is evident, then, that the greater part of the fat, if not the whole 
of it, must be absorbed by the epithelial cells from the intestine. It 
is also very improbable that these cells take up the fat in the form of 
an emulsion. As has already been stated, the structure of the cell is 
unsuitable for such a function, and, in addition, fat granules have never 
been observed in the broad striated border. This almost amounts to a 
demonstration that the fat passes through the border of the cell in some 
soluble form, and is afterwards thrown down in a particulate form, as the 
result of a process of cell metabolism. 
Emulsion theories of fat absorption are therefore being gradually 
replaced by theories of absorption in solution. These theories must 
next be discussed, but before doing so reference may be made to another 
emulsion theory of fat absorption introduced by Munk. 
Theory of I. Munk. — Munk 5 showed that fatty acids can be 
emulsified under exactly the same conditions as rancid fats, and further 
that these fatty acids are capable of absorption, and can completely take 
the place in the animal economy of neutral fats, being in great measure 
1 v. Thanhoffer, Arch. f. d. ges. Physiol., Bonn, 1S74, Bd. viii. S. 391 ; Fortuuatow, 
ibid., 1877, Bd. xiv. S. 285. 
2 These wandering celts ( Wanderzdlen) were first described as occurring in the epithelium 
by Eberth (JFiirzb. rued. Ztschr., 1864, S. 23); Arnstein (Virchow's Archiv, 1867, Bd. 
xxxix. S. 537) first mentioned the presence of fat granules in them. 
3 Arch. f. d. ges. Physiol., Bonn. 1SS3, Bd. xxxi. S. 231. 
4 Schafer, Internal. Monatschr. f. Anat. v. Eistol., Leipzig, 1S85, Bd. ii. S. 6. 
5 Verhandl. d. Berl. med. Gesellsch., March 1879 ; Arch./. Anat. u. Physiol., Leipzig, 
1879, S. 371 ; Virchow's Archiv, 1SS0. Bd. lxxx. S. 10: ibid., 1884, Bd. xcv. S. 409; Ztschr. 
f. physiol. Clicm., Strassburg, 1885, Bd. ix. S. 568; Arch. f. Anat. u. Physiol., Leipzig, 
1890, Supp. Bd., S. 138. See also v. Walther, ibid., 1890, S. 329. 
