It varies in its proportions, as we examine the regions of the spine, the neck, the chest, the abdomen, and pelvis.
Vertebral cellular texture.
I so call the cellular texture which is found in the neighbourhood of the spine, and in the vertebral canal.
In the cavity of this canal, there is but very little of it. Between the tunica arachnoides and the medulla oblongata, between the nervous elongations that go from the last, and the sheaths of the arachnoides that accompany them, we see some filaments that follow the course of the vessels, and contribute to the formation of the pia mater. There is none of this texture between the arachnoides and dura mater. Below this, between it and the vertebral canal, in the places where it does not adhere, there is more of it, especially below, where it is very loose, and always covered with a fluid that is often reddish.
On the outside of the spine, we see, behind, many muscles and but little cellular texture in proportion; thus, depositions in this part are much more rare and much less liable to spread than elsewhere, a circumstance which arises also from this, that the muscles being very compact in the vertebral canals, keep in a state of depression the cellular texture that separates them.
This texture is on the contrary very abundant along the whole course of the anterior part of the spine, in the neck, where it accompanies the carotids, in the thorax and abdomen, where it follows the course of the aorta, the great trunks which go from it, the vena cava, azygos, &c. There is no part of the animal economy, more frequently exposed to different collections of pus, than this. Nothing is more common than to see depositions that are formed at the anterior part of the thorax and abdomen, projecting at the groin by a channel which we discover by the examination of bodies. It is principally by these cellular communications, and by those which are beneath the integuments, that the superior parts correspond with the inferior, and vice versa.
Cervical cellular texture.
The neck, which is very muscular, has much cellular texture, besides that which belongs to the vertebral column. It is especially in the lateral parts, where the lymphatic glands are situated, that this texture is remarkable. In the space between the sterno-cleido-mastoideus and trapezius muscles, where the brachial nerves arise, and where the vessels pass that go from the thorax, there is a great quantity of it. It communicates with that of the thorax, by the large opening that is found at the superior part of this cavity; hence it happens, that when the cells of the lungs are ruptured, the escaped air occupies first the chest and then the neck, and hence also the facility with which we produce the same phenomenon by forcing air beneath the pleura of a dead body, &c.
The cellular texture of the neck communicates also with that of the superior extremities above and below the clavicle. Hence why the neck and consequently the chest, are filled with air, water, and other fluids that are forced into the sub-cutaneous and intermuscular texture of these extremities.