218 LYMPHATIC AND 
_ The colour of the lymphatic gland, a ane ing 
apparently on the contents of its bloodvessels, 
is of a pale rose — resembling in this re- 
spect the colour of the salivary glands or of the 
cineritious matter of the brain; the exceptions 
to this observation will be found in the mesen- 
teric glands while the chyle is passing through 
them, when they assume a whitish colour; the 
lymphatic glands in the neighbourhood of the 
liver and gall-bladder have been pepsi to 
possess a slight yellow tinge, but this is to be con- 
sidered a si dear appearance. The black 
colour of the bronchial glands is remarkable and 
not easily accounted for; the lymph passing 
from the lung to them being always perfectly 
transparent and colourless. 
The lymphatic gland has a capsule of con- 
densed cellular tissue, which surrounds it and 
firmly adheres to it, appearing to send cellular 
prolongations into its substance ; the outer sur- 
face of this capsule is connected to the surround- 
ing textures by a loose cellular tissue. The 
capsule appears to serve the purposes of convey- 
ing the bloodvessels to the interior of the gland, 
of isolating it from the surrounding parts, and 
of preventing its over-distension by the lymph 
conveyed to it. 
The bloodvessels of the lymphatic glands are 
large and distinct; frequently more than one 
artery is traced to a gland; the returning veins 
do not generally correspond either in direction 
or‘number with the arteries. The veins are 
much larger, but have appeared to me fewer in 
number than the arteries. 
Nerves of considerable size pass to the lym- 
-phatic glands and can generally be traced 
through them, from which circumstance it has 
been doubted whether any filaments are left in 
the gland; but if acute sensibility to pain from 
undue pressure or from disease be adinitted as 
dependent upon a proper supply of nerve, un- 
doubtedly they possess it. a e exact mode of 
arrangement of the bloodvessels in the interior 
of the gland is not well known. Aftera success- 
ful injection of these vessels the gland assumes 
the same colour as the injection itself. 
Our knowledge of the structure of the ab- 
sorbent glands rests mainly upon the informa- 
tion obtained by throwing injections of mercury 
or coloured wax into the lymphatic vessels. In 
this mode of investigating their texture, the walls 
of the canals or cavities containing the injection, 
which appear, as in the kidney and testicle, to 
form the parenchyma of the organ, are com- 
ressed, and when dry become transparent. 
he arrangement of the minute bloodvessels on 
the lining membrane of these canals has not 
been sufficiently investigated, and until this 
has been effected, our knowledge of the structure 
and function of the lymphatic gland must be 
considered very unsatisfactory, and as consist- 
ing of little more than conjecture. The great 
point of controversy has been, whether the in- 
jection thrown into the gland by the afferent 
ymphatic vessels was contained in cells or in 
convoluted vessels, which if decided would 
throw but little light upon the office performed 
by the gland—a desideratum in physiology of 
considerable importance, and without which 
LACTEAL SYSTEM. 
we are left in the dark at the very thresho 
of our investigations with respect to 
changes effected in the lymph and chyle 
advance towards sanguification. On examinin 
Fig. 52. eo 
oT 
Lymphatic glands iajones with mercury. 
( After ™ 
A, gland injected and dried. a@, a, vasa a 
rentia. b, vasa efferentia. 9 
B, gland injected and laid open to show the 
rent cells. i, apparent cells; e, vas efferens; 
vasa afferentia., 
the glands thus distended with injections, ¢ 
vasa inferentia are seen reaching the g 
from various sources, and on their appre 
it they may be observed to subdivide in 
tremely minute branches, which disapp 
plunging into its substance: equally mina 
vessels may be observed emerging from 
opposite side or surface, which soon unite 
form the vasa efferentia of the gland ; the gla 
itself, which is intermediate in position betwe 
these vessels, when injected, presents a gi 
nular surface, and at first sight an obse 
would generally conclude that he was lo 
ing upon minute cells filled by the injec 
in making a section also into the substa 
of the gland and allowing the mercury — 
escape, the appearance on a supe 
spection is still that of cells; proceedit 
however, with more attention to examine 
supposed cells, especially after making a sect 
as close to the surface of the gland as possib 
by the aid of the microscope it will be evide 
that tubes closely set together and adherent 
each other, have been laid open, passin 
various directions, and in their interior ma 
valvular constrictions and thread-like inters 
tions may be seen; in fact the gland appea 
to be entirely composed of a convoluted 
the sides of which as they come in contact are 
firmly held together by cellular membrane 
derived from the capsule. — 
This convoluted tube forming the gland is no 
always cyl'ndrical, but is occasionally dilated 
and looks fattened near the surface where 
pressed by the capsule; the size of this tub 
. 
iCclal 
