ANATOMY OF THE ALIMENTARY CANAL. 
453 
as to the manner in which fat traversed the villus : Henle (15), Schwann (16), Dondees 
(12), Kollikee (44), and Beuch (18). Dondees further spoke of the chyle-vessels as 
possessing a membrane. 
Henle (15), 1837, showed that the intestine is covered by a layer of epithelium. 
Goodsie (7), 1842, first noticed that the epithelial cells apparently contain fat- 
granules. He did not, however, lay any stress on the fact, but supposed that certain 
“ vesicles ” close to the membrane have the property of absorbing, and that the epithe- 
lium is cast off previous to absorption. This author saw the membrana propria clearly, 
and considered that the nuclei situated in it at regular distances were the germinal 
spots from which the epithelium is reproduced. 
Lacauchie (19), 1843, first noticed the movements of the villi, and attributed them to 
a system of muscles. He considered each villus to be a system of sucking- and forcing- 
pumps ( aspirantes et foulantes). 
Geuby and Delafond (20), 1842 and 1843, found chyle in the epithelial cells, and 
thought that each epithelial cell must be considered an organ specially charged to receive 
raw chyle, and convert it to a homogeneous chyle, and to transmit the liquid thus made. 
Each epithelial cell is provided with a cavity whose external opening is sometimes 
gaping and at other times more or less exactly shut. They found that on the surface of 
the epithelium of the villi of the dog vibratile bodies exist, whose function may be to 
displace, when necessary, the raw chyle in contact with the epithelium. They inde- 
pendently discovered the movements of the villi. 
E. H. Webee (8) noticed that the chyle-vessels were filled with chyle, although the 
mucosa was clothed with its epithelium ; and no one after this seems to have doubted 
that the fat found its way through the epithelium, if we except Eedmann (34). Webee 
speaks of a second layer of cells which are round, some of which are filled with an opaque 
white fluid and some with a transparent fluid. He considered that the epithelium 
underwent a change in form in the act of absorption. 
Feeeichs (11), 1848, found that the granules of fat, which are of considerable size in 
the stomach, become finer in the intestine, this change being of a mechanical nature, 
probably caused by the action of bile, the pancreatic fluid, and the fluid of the 
intestine ; he found that the fat thus finely divided presses gradually through the sub- 
stance of the villus. 
Eunke (21), 1853, in his Atlas, gave a representation of the branched chyle-vessels 
(see fig. i. Taf. viii.). 
Eunke (13) afterwards (1855) spoke of the chyle-capillaries as being due to the fat 
pressing in everywhere in the tissue of the villus. He denied the existence of pre- 
formed ways. 
Beuch (18), 1853, said that the fat enters the epithelial cells as little drops, which 
unite to form larger ones. He spoke of fat-absorption by the blood-vessels, and con- 
sidered all the so-called branched chyle-vessels to be really blood-capillaries containing 
molecular fat ; he included in that Funke’s fig. i. Taf. viii. 
