133 



*he body, seldom insulated, but in clusters in the hollows of the ham, 

 the arm-pit, in the bends of the groin and elbow, along the iliac vessels, 

 the aorta and the blood-vessds of the neck, around the base of the jaw 

 and of the occiput, behind the sternum, along the internal mammary 

 vessels, lastly, within the mesentery, in which their number and size bear 

 a proportion to the quantity of absorbents which pass through them. 

 These reddish glands* varying in size, of an oval or globular form, have 

 two extremities, the one at which the lymphatics enter : they are then 

 called " ajferentia" and the other extremity turned towards the thoracic 

 duct, which sends out vessels, fewer in number, but of a larger size, and 

 called u efftrentia" from their use. 



The lymphatics, on reaching the glands, divide, unite again and inos- 

 culate, they likewise bend back on themselves, and thus form the tissue 

 of the conglobate glands, which are merely clusters of coiled vessels, 

 united by cellular tissue, in which blood-vessels are distributed, so as to 

 occasion their reddish colour. The coats of the lymphatics are thinner 

 in the glands than elsewhere; and their dilatations, their divisions, and 

 their anastomoses, are likewise more frequent, while they are in the glan- 

 dular tissue. All the lymphatic vessels, whose course lies in the direc- 

 tion of a gland, do not enter its substance, several pass by the gland and 

 embrace it, forming around it a sort of plexus, of which the ramifications 

 are directed towards other glands, more in the vicinity of the thoracic 

 duct. The lymphatic glands form so essential a part of the absorbent 

 system, they produce on the lymph such indispensable changes, that no 

 lymphatic vessel enters the thoracic duct, without having previously 

 passed through these glands. It even frequently happens, that the same 

 vessel passes through several glands, before opening into that common 

 centre of the lymphatic system. Thus, the vessels which absorb the 

 chyle of the intestinal tube, pass several times through the glands of the 

 mesentery. The lymphatics of the liver, situated very near to the re- 

 ceptaculum of Pecquet, have been thought, by some anatomists, not to 

 follow that general rale ; but there are uniformly found, in the course 

 of these vessels, glands which they enter. As, however, the glands are 

 few in number, the lymph conveyed from the liver, is only once subject- 

 ed to the action of the glands ; and this circumstance appears to me to 

 explain, in a satisfactory manner, the transmission of the colouring mat- 

 ter of the bile, which, in jaundice, manifestly discolours the blood, in 

 which M. Deyeux found it by chemical analysis. 



XLV. The parietes of the lymphatic vessels are formed of two coats, 

 both very thin and transparent, yet very strong, since they support the 

 weight of a column of mercury, which would rupture the coats of arteries 

 of the same calibre. The internal coat, which is the thinner of the 

 two, forms valvular folds, arranged in pairs, like the valves of the veins, 

 and like them preventing a retrograde circulation. Although these coats 

 are very strong, and likewise very elastic and contractile, as they may 

 be seen to contract, and to expel the lymph with great impetus, when 



* It is with a view of conforming to the language in common use, that I give the 

 name of gland to those coils of lymphatic vessels, which are totally cliff ere nt from the 

 real conglomerate or secretory glands. It might be better, perhaps, to call them^an^- 

 lionsy as has been done by my learned and respected colleague Chaussier, though that 

 name is objectionable, from its association in the mind with the nervous ganglions, 

 whose structure is not at all similar to that of the lymphatic ganglions. Author's .l\"ot,\ 



