22 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
other, it is also possible that the glycerine absorbed may either be used as a source 
of energy by these cells, or allowed to pass on, and the fatty acid later united in the 
cell to other glycerine synthetically formed by chemical processes going on in the 
cells in which the synthesis of fat from fatty acid or soap occurs. 
Although it is fairly certain that a hydrolysis of fat occurs in the intestine and 
a re-synthesis before the thoracic duct is reached, there is, at the present time, no clear 
experimental evidence as to the situation in the course of absorption at which the 
synthesis is effected, or as to the agency by which the synthesis is brought about, that 
is to say, as to whether it is due to an intra-cellular enzyme, or is a process in which 
the living protoplasm acts as the energy transformer. 
The experiments recorded in this communication were designed with the object 
of shedding light on these points. 
There are two chief places at which the lymph, carrying the absorbed fatty 
constituents, either comes into intimate relationship with cells, or is forced to pass 
through them, viz., first, in the intestinal wall itself, in the columnar lining cells and 
adenoid tissue of the villus lying between these and the central lacteal, and secondly, 
in the abdominal lymphatic glands, through which the chyle all passes on its way to 
the thoracic duct. It is hence at these two situations that chemical changes may be 
expected to occur, and the suggestions naturally present themselves of examining the 
composition of the chyle as regards fatty constituents, before and after passing these 
points, and of studying the action of these tissues upon the constituents involved in 
the synthesis of neutral fats. 
There is no question that the intestine during fat absorption contains both fatty 
acids and soaps in solution, and Munk has shown, as above stated, that the lymph of 
the thoracic duct during fat absorption contains nearly all its fatty matter as neutral 
fat ; but the most difficult point in the course, from which to obtain lymph in sufficient 
quantity for chemical analysis of its fatty constituents, is the portion lying between the 
intestine and abdominal lymphatic glands, for the mesenteric lacteals are far too small 
to admit a cannula. 
As far as the writer is aware, no analyses have hitherto been published of the 
fatty matter contained in the chyle of the mesenteric lacteals, but, by a method, which 
will be described later, a sufficient supply of fatty chyle was obtained to demonstrate 
most clearly that already, in the mesenteric lacteals, practically all the fatty matter is 
present as neutral fat. 
It has long been known, from histological evidence, that a change occurs in 
the absorbed fatty constituents in the columnar cell. For such cells, taken some 
hours after a fatty meal, when examined under the microscope after appropriate fixing 
and staining, are seen to be filled, except in the striated border, with globules of 
varying size, which present all the histological appearances and reactions of fatty 
material. 
