86 
ON THE MESENTERIC VEINS. 
have been brought forward by modern physiologists arc quite 
sufficient to convince us that i\\Q ininciijal function of the lacteal 
vessels is to take tip, in the form of chyle, the more solid, di¬ 
gested, or dissolved portions of the nutritive substances admitted 
into the alimentary canal; and, without these vessels having any 
communication whatever with the mesenteric veins or liver, they 
are enabled to convey their contents to the receptaculum chyli 
and thoracic duct. 
On the other hand, as far as regards those fluids which do not 
undergo so true an assimilated process, and in which various he- 
trogeneous substances are occasionally introduced, I have already 
stated, that I have not the least doubt that they are absorbed 
by the extreme radicles of the mesenteric veins, and afterwards 
pass to the vena potarum, and through the liver, as already 
stated. 
But to contend, as is stated in the second position, that the 
lacteal absorbents communicate with the mesenteric veins 
through the lymphatic glands, and that by such means a part of 
the chyle is enabled to pass too, and ultimately circulate with the 
venous blood through the liver, while, on the other hand, the 
other portion of the chyle is supposed to pass as in the common 
acknowledged way to the receptaculum chyli and thoracic duct, 
is, in my idea, to maintain that which is unsupported by any 
proofs, either anatomical or physiological. 
If we minutely examine the structure of these lymphatic 
glands, we find that the very small veins already spoken of, and 
which are those through which this communication is supposed to 
take place, instead of, as imagined, having any thing what¬ 
ever to do with the lacteal vessels, do, in place thereof, take 
their extreme origin from, and are only the corresponding red 
veins belonging, to, those small arterial branches v»?hich are given 
off from the trunks of the mesenteric arteries at the root of the 
mesentery ; and which arteries, no doubt, are for the purpose of 
supplying not only the substance of the glands, but also the im¬ 
mediate surrounding portions of the mesentery With, blood for their 
support. 
These arteries, therefore, like the arterial branches in other 
parts of the body, are found to terminate in two orders of vessels; 
that is, first in veins which convey back the red blood toward the 
centre of the circulation, and which are those just mentioned, and 
secondly, by their extreme terminations in the minute radicles 
of the transparent or white veins, that are more commonly called 
lymphatic vessels; and which lymphatic vessels are proved to 
be the second class of lacteals. 1 have proved this fact some¬ 
time ago myself (see the Lancet); and I am happy to find from 
