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DR. HERBERT WATNEY OH THE MINUTE 
CHAPTER I. 
THE MINUTE ANATOMY OF THE MUCOUS MEMBRANE OF THE INTESTINE, AND THE 
METHOD OF FAT-ABSORPTION. 
In this chapter I propose first to state very briefly the result of my researches on the 
structure of the intestine and the method of fat-absorption ; secondly, to relate the his- 
tory of these subjects ; and, finally, to give a detailed account of this research. 
Preliminary Statement. 
The mucous membrane of the intestine is pervaded everywhere by a reticulum similar 
to, and continuous with, that found in the follicles of Peter’s patches. This reticulum 
is situated among all the other elements which are contained in its meshes. This is true 
of the epithelial cells, the muscle-fibres , the cells of the parenchyma, and of the endo- 
thelial plates of the membrana propria, of the blood-vessels, and lymphatics. 
It is by this reticulum that the fat is absorbed, and by this reticulum that the fat finds 
its way into the lymphatic vessels, and probably also into the blood-vessels. 
History. 
Asselius (1628) ascribed open mouths to the chyle-vessels of the intestine. 
Lieberkuhn (1)*, Heweon (2), and Cruikshank (3) believed that the central canal of 
the villus opened on the surface. Lieberkuhn thought he saw one opening from 
the ampulla or widened end of the chyle-vessel. Hewson conceived that the villi have 
a network of lacteals, and that the orifices of the lacteals are on the extremities of the 
villi. He considered it probable that the villi were erected “ in order to make the small 
absorbents stand rigidly open ; ” and he thought that in this way the fluid (chyle) may 
be conveyed to the first pair of valves. Cruikshank saw “ in some hundred villi the trunk 
of a lacteal forming or beginning by radiated branches. The orifices of these radii were 
very distinct on the surface of the villus, as well as the radii themselves. The radii 
passing into the trunk of the lacteal were full of a white fluid. There was but one 
trunk in each villus.” 
Pudolpiii (4), 1802, examined the villi of many animals ; he denied the existence of 
openings of the chyle-vessel on the surface ; he imagined that the chyle-vessels took 
their rise by a network within the villi. 
Fohman (5), 1827, injected the lymphatics of fish with quicksilver. He found that 
no mercury escaped into the intestine, and concluded that the lymphatics end blindly. 
After this there was a long contest as to the origin of the chyle-vessel and method of 
fat-absorption. We may distinguish three different opinions. The first was that the 
chyle-vessel arose from a network of lymph-capillaries : Krause (6), Goodsir (7), E. H. 
Weber (8), Nuhn (9), Zenker (10). A second opinion maintained that the fat pressed 
through the villus, not in definite preformed ways, but among the parenchyma: 
Frerichs (11), Donders (12), Funke (13), Donitz (14). A third opinion was held by 
other observers, who maintained that the chyle-vessels are closed ; they gave no opinion 
* See the References, p. 486. 
