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LYMPHATIC AND LACTEAL SYSTEM. 
is much larger than that of the branches of the 
vasa afferentia and efferentia, a fact that has 
been too much overlooked by anatomists, and 
which leads me to conjecture that these vessels 
enter and arise from its convolutions by open 
mouths; be this as it may, we know that the 
injection conveyed into the gland by the vasa 
afferentia readily passes from it by the vasa 
efferentia. I should not here omit to mention 
a circumstance already adverted to of consi- 
derable interest, viz. that the injection conveyed 
to a gland by an afferent vessel is occasionally 
teceived by the veins of that gland, and to all 
appearance without rupture or extravasation. 
The occurrence itself is admitted by all; but 
physiologists differ much in their explanations 
of the channel by which the injection has en- 
tered the vein. Some explain it by an extrava- 
sation into the cellular tissue from an injury 
by which both sets of vessels have been opened ; 
others, who conceive that a minute net-work of 
lymphatics exists on the interior of the veins 
and arteries, will have no difficulty in ima- 
gining a rupture of this net-work; the vasa 
vasorum of the lymphatics, which may be dis- 
tinctly seen on their interior after a minute in- 
jection, may be supposed to have given way 
and to have admitted the injection from the 
interior of the lymphatics. . But these opinions 
will not explain. -why this communication 
should take place within the gland only, and 
invariably with the vein, never with the artery. 
The general opinion is that this communi- 
cation takes place accidentally, and not by 
any real continuity of canal. Johmann stands 
almost alone in asserting thata natural commu- 
nication does exist between the lymphatics and 
veins within the glands, especially in those 
Situations where in birds, reptiles, and fishes, 
the lymphatics have been proved to terminate 
directly in the veins. Fohmann even ventures 
an opinion as to the mode in which the lym- 
phatic joins the vein ; not, he conceives, by con- 
tinuity of peripheral branches, but by an effer- 
ent lymphatic opening into the side of a vein 
before the latter emerges from the gland. 
Without committing myself to the exact mode 
of union, I must confess I agree with Fohmann 
that a natural communication does exist in 
some of the glands between the lymphatics and 
the veins. It has been observed hundreds of 
times. It has occurred to every anatomist who 
has engaged himself with the injection of these 
vessels; I have met with at least twenty such 
instances myself, while a similar communica- 
tion between a lymphatic and artery within a 
gland has never been observed. I am entirely 
ata loss, therefore, to account for these occur- 
Tences without admitting a natural channel to 
exist between the one set of vessels and the other. 
I have before observed that the exact arrange- 
ment of the bloodvessels in the interior of the 
canals of which the glands are constituted, is 
not known ; but we are equally in the dark with 
respect to the vascular supply received by other 
minute tubes, such as the seminiferous, urini- 
ferous, and lactiferous tubes, from the capilla- 
ries of whose lining membranes, however, we 
admit that their appropriate secretions are de- 
219 
rived. As far, then, as organisation is con- 
cerned, there is nothing to forbid our ascribing 
a secreting function to the interior of the 
canals of the lymphatic glands, or of theNym- 
phatic vessels generally. There can be little 
doubt but that the lymph and chyle undergo 
modifications in their passage through the ab- 
sorbent glands, although we are not at present 
prepared to state the nature of that modification. 
It has been observed that the chyle included 
between two ligatures in its own vessel before 
it has reached a gland will not coagulate, 
although after it has passed the gland coagula- 
tion readily takes place. Miiller remarks 
from this circumstance that the glands of the 
mesentery appear to have the power of changing 
part of the albumen of the chyle into fibrin. 
At any rate we are warranted, from the little we 
do know ofthe structure of the absorbent gland, 
in asserting, that the chyle and lymph collected _ 
from various sources must be mingled together 
in the glands, that they must be divided into 
extremely minute streams on their entrance 
into or exit from a gland, that they must be 
submitted to a great extent of surface of their 
containing vessels, and subjected to considera- 
ble delay in their passage through the gland. 
Mr. Gulliver’s observations on the fluid con- 
tained in the absorbent glands would almost 
lead us to conclude that their proper office was 
to fabricate the peculiar globule of the lymph 
and chyle; my own observations on these fluids 
before and after reaching the glands would 
not bear out this opinion; but as I have next 
to consider the characters, physical, microsco- 
pical, and chemical, of these fluids, I shall 
shortly enter more fully into this subject. 
Lymph is a transparent fluid, slightly opa- 
line, of a light straw colour ; its specific gravity 
is 1022°28, water being 1000°00; its odour, 
which is slight, varies, and is peculiar to each 
animal ; it is alkaline, and has a saline taste. I 
collected in an ounce-phial about three drachms 
of lymph from a large lymphatic in the axilla 
of a horse, by inserting a small silver tube into 
it. In about ten minutes the whole had coa- 
gulated into a jelly-like mass ; in half an hour 
a separation had taken place into a fluid and 
solid part: the latter formed a soft tremulous 
clot modelled to the form of the phial. A 
drop of this lymph placed on a piece of glass, 
and covered by talc, was submitted to inspec- 
tion under the microscope, immediately after its 
removal from the vessel. A number of colourless 
spherical globules were observed in it havinga 
granular surface, and precisely resembling those 
described by Mr. Gulliver as belonging to the 
mesenteric, lymphatic, and thymus glands. I 
am not aware whether Mr. Gulliver considers 
these globules as belonging exclusively to the 
glands, or whether he thinks them distinct 
from or identical with the lymph and chyle 
globule. My own observations lead me to 
state that they are found in the lymph or chyle 
before and after passing the glands, as well as 
in their transit through them. Iam also dis- 
posed to assert that these globules remain co- 
lourless, and that whenever the lymph possesses 
a slightly red tint, it obtains that tint from the 
