122 
ANATOMY OF THE HORSE. 
Communication .—The superficial and deep-seated vessels 
communicate veiy frequently with each other, and never fail to 
send off, in addition, other anastomotic branches to whatever 
solitary absorbents there may be in the vicinity. The glands, 
likewise, are linked together by absorbent tubes of inter-commu¬ 
nication running from one to the other. 
Demonstration .—The following different methods of proceeding 
with a view to demonstrate these minute and ordinarily hardly 
visible vessels, are extracted from the laborious and accurate 
researches of the late celebrated anatomist, Mr. Cruikshank :— 
In an animal opened alive, some hours after it has been fed, 
the lacteals are seen turgid with chyle: they may also be made 
visible by throwing coloured thin fluids into the intestines; or, by 
making ligatures on the trunk of the anterior mesenteric artery, 
which will include the trunk of the absorbents. An eye ac¬ 
customed, readily distinguishes lacteals upon the intestines from 
arteries and veins, even when they are collapsed and empty : 
punctures may be made with a lancet, and the vessels injected 
with quicksilver by means of a tube formed expressly for that 
purpose. I have sometimes injected lacteals from punctures 
made by the sides of veins, where I knew they must be, though 
they were then invisible to the naked eye. 
Upon the liver and lungs lymphatics are frequently visible, 
and maybe injected by puncturing one of the small branches; 
but the valves almost always make the injecting of them from 
the trunk to the branches impracticable. Pressure in the course 
of the absorbent circulation will commonly force from the extreme 
branches into the trunks some little reddish or brownish fluid, 
making the latter visible, which may then be punctured and in¬ 
jected.—Watery fluids thrown into the arteries, veins, or ducts of 
glands, very commonly get into the absorbents, and render them 
visible.—One of the best methods is to previously inject the arte¬ 
ries and veins of the part, and afterwards macerate it for some 
days: putrefaction then takes place, air is generated in the cel¬ 
lular membrane, whence it gets into the orifices of the lymphatics, 
and uniformly fills their branches.—The best subject for these 
injections is one whose limbs are without fat and are dropsical, 
but not too much so. 
In parts where glands are to be found, it is only necessary to 
puncture the gland, and introduce a tube filled with quicksilver, 
or push the pipe into its substance without any previous punc¬ 
ture. The mercury thus fills the cells of the gland, and from 
these the lymphatics. The thoracic duct itself is most suc¬ 
cessfully injected in the same way, that is, either from glands 
upon the mesentery, upon the bodies of the lumbar vertebrae, or 
