ANATOMY OF THE ABSORBENT SYSTEM. 287 



Each lymphatic gland is surrounded by a capsule, resembling 

 condensed cellular substance, which adheres very closely to the 

 gland, and from which cause many anatomists are disposed to 

 deny its existence, at least as a* distinct membrane. They are 

 also abundantly furnished with arteries and with veins destitute 

 of valves; but though they are penetrated by nervous filaments, 

 it is not yet satisfactorily ascertained that any remain with them; 

 it is, however, more probable than otherwise. Their connexion 

 with the surrounding cellular substance is sufficiently loose to 

 permit them, in certain parts, to be slid moderately backwards 

 and forwards. When this motion is arrested, it is from inflam- 

 mation about them. 



The capsule of the lymphatic gland, like that of other glands, 

 sends processes within to keep its parts together, and to con- 

 duct the blood vessels. It also contains a peculiar fluid called, 

 by Haller, succus proprius, which is principally found in young 

 animals, diminishes as they advance in age, and finally disap- 

 pears. It is of various colours, but more frequently white; it 

 appears to have globular particles in it, which the late Mr. 

 Hewson, for divers reasons, thought to become afterwards the 

 red globules of blood. 



When a lymphatic gland is injected with quicksilver, it ap- 

 pears to be made up by the minute branching of the vasa infe- 

 rentia, and the roots of the vasa eflerentia, the former being con- 

 tinued into the latter. There is also some appearance of small 

 cells intermediate to these two orders of vessels. AH anato- 

 mists admit the former opinion; but many reject the latter, un- 

 der a presumption that the appearance is delusive. The argu- 

 ments, however, seem to be in favour of their existence. Mr. 

 Cruikshank,* whose address in these matters was certainly of 

 the first order, declares that he never failed to perceive them, 

 and particularly well, just as the mercury was entering the 

 gland. This arrangement is still more readily made out in 

 animals, as the horse, ass, mule. It also seems, from his ob- 

 servations, that when there are more than one vas inferens and 

 efferens, there are cells for each set, which are kept distinct 

 from the cells of the others, though they communicate freely 

 with their cognates. Mr. Abernethy's investigations, on the 



* Loc. cit. p. 85, pi. iii. 



