These glands are scattered in the different parts in greater or less
number. In the superior and inferior extremities, we find but a small
number, except at the upper parts, the axilla and the groin. In the
ham and at the elbow there are some, and there are engravings of them
at the instep. But upon the arm, the leg, the thigh, the fore-arm, &c.
they are not found. It is about the articulations that all are met
with; in this respect, we can say, that they are constantly increasing
from the inferior to the superior, no doubt because in ascending the
number of absorbents is continually increasing.
Not numerous on the cranium, they are only on the exterior of this
cavity, no one has ever, I believe, been found within it; which proves,
perhaps, that it is not the tenuity of the absorbents that conceals
them from us there, but that it is because they are of a peculiar
nature and different from that of the others. The face contains many of
these glands, especially along the stenonian duct, upon the buccinator,
&c.
As to the trunk, if we take the vertebral column for a term of
comparison, we shall see that there are but very few lymphatic glands,
hardly any at its posterior part, and that they are very numerous
anteriorly. On the neck, the jugulars are accompanied by a great series
of these glands. In the thorax, the posterior mediastinum contains many
of them. In the abdomen, they are abundant along the vertebral column,
behind the mesentery.
The whole interior of the thoracic and abdominal cavities, considered
otherwise than as it respects the spine, is also furnished with
them. They are very near each other in the mesentery, at the root of
the lungs, around the bronchiæ and in the pelvis. We see from this
arrangement, that, 1st. the lymphatic glands are found in general more
numerous in the places where the cellular texture predominates, in
which they are, as it were, buried, a remarkable relation for which
we are unable to assign precisely the reason. There are but few parts
abounding with this texture, that do not also abound with lymphatic
glands, and reciprocally there are none of these glands where it is
wanting. 2d. We see also that the parts the most distant from the
common trunks of the absorbents, as the extremities, the head, the
back, &c. are less provided with these glands; that the nearer we
approach these common trunks, the more numerous they become; so that
we might say that they form around them a sort of boundary, which
separates them from the secondary absorbents, and which at the same
time makes them communicate with them.
The size of the lymphatic glands, is variable, from the tenth of a
line in diameter, to the size of a hazle-nut, and even larger. They
are oftentimes so small that we can with difficulty discover them, and
they cannot sometimes be seen until disease has developed them. Their
increase in size is an ordinary effect of scrophulous affections,
which often show us lymphatic glands in places where we did not know
that they existed, especially on certain parts of the face and neck.
We cannot say then that the swellings of the cellular texture deceive
us; for the comparison of these bodies, which are thus made evident by
the disease, and which no doubt pre-existed, with the known lymphatic
glands, and which are then found equally swelled, proves their perfect
identity. All exhibit either the same fatty and white substance, or the
same caseous pus, according to the period of the disease.
In general these glands are much developed in childhood, diminish in
the adult, and almost disappear in old age. They are, it appears to
me, a little more evident in women than in men, in the phlegmatic
temperaments than in the sanguine. Of all the different enlargements of
which they are capable in different places, the tabes mesenterica gives
them the greatest size.
Their form, sometimes oval, sometimes more or less elongated, always
tending to a round one, which is generally that to which all the organs
of animals, and even all those of organized bodies are disposed; whilst
those of inorganic bodies assume those of cubes, prisms, &c.
The lymphatic glands, sometimes insulated as in the extremities of the
limbs, collect in greater number as they approach their common trunks.
The axilla and the groin contain many of them, as I have already said;
but in the abdomen, they are united in a group, and are so close to
each other in the mesentery, that they have appeared to Azelli to form
in this place, not an union of organs, but a single one, which he has
taken for a second pancreas, and to which he has given his name.