602 
ON THE LYMPHATICS. 
lungs and of the peritoneum gorged with blood. He concluded 
from this, that these vessels had absorbed the fluid by which 
they were filled : but I have often found, both in animals and in 
man, lymphatics distended with blood, in cases in which there 
had been no effusion of that fluid ; and besides, there is, in 
certain cases, so little difference between the lymph and the 
blood, that they cannot be easily distinguished/’ In another 
place he observes, “ Whence, then, comes the fluid that is found 
in the lymphatic vessels ? or, in other terms, what is the real or 
probable origin of the lymph ? In considering, first, the nature 
of the lymph, which has the greatest analogy with the blood; 
secondly, the communication demonstrated by anatomy between 
the termination of the arteries and the radicles of the lymphatics; 
thirdly, the facility and quickness with which colouring or saline 
substances introduce themselves into the lymphatic vessels, it 
becomes, in my opinion, very probable, that the lymph is a part 
of the blood, which, in place of returning to the heart by the 
veins, follows the course of the lymphatic vessels*.” Magendie 
immediately remarks, that “ this is by no means a new idea, 
but nearly the same as that of the anatomists who first discovered 
the lymphatic vessels, and who supposed that these vessels were 
intended to carry back to the heart a part of the serum of the 
blood.” 
Our countryman, the late Mr. Cruikshank, has also noticed 
the fact of the lymphatic vessels being frequently found to con¬ 
tain red blood in animals dying from inflammation of the lungs, 
peritoneal inflammation, strangulation, and other violent deaths ; 
these vessels were discovered to be turgid with blood, without 
the least appearance of the extravasation of this fluid into the 
cellular membrane. 
From the extracts which I have quoted from Magendie, it 
appears that this physiologist considers the red blood so often 
found in the lymphatic vessels to be transmitted from the mi¬ 
nute terminations of the seriferous arteries into the extreme 
radicles of the lymphatics; and in this view of the subject I 
perfectly accord with him. 
Having, I am afraid, departed a little too far from my sub¬ 
ject, in relating what has already been advanced by authors, I 
shall return to what has occurred under my own observation. 
From having at that time an important subject already under 
investigation, viz. the varied changes which might occur in the 
second class of lacteal vessels, I was induced to attend also very 
minutely to the different changes which might take place in the 
* Page 317, 323. 
