LYMPHATIC APPARATUS. 



667 



Fig. 259. 



ramifications. 1 M. Magendie 2 conceives the most plausible view regard- 



ing the lymphatics to be: that they arise by extremely fine roots in 



the substance of the membranes and areolar tissue, and in the paren- 



chyma of organs, where they appear continuous with the final arterial 



ramifications; as it frequently happens, that an injection sent into an 



artery passes into the lymphatics of the part to which it is distributed. 



By some, they are described as commencing either in closely meshed 



networks, interspersed among 



the bloodvessels of the several 



tissues, or else in pointed closed 



tubes or processes, as shown in 



the marginal figure of the lymph 



and bloodvessels in a part of 



the tail of the tadpole; the 



bloodvessels being denoted by 



the corpuscles in them. In this 



state, many of the extremities 



of the lymphatics appear to 



communicate with pointed or 



star-shaped cells; but this, ac- 



cording to Messrs. Kirkes and 



Paget, 3 may be peculiar to the 



embryonic state, as no similar 



cells are seen in the adult; nor 



is there any appearance of the 



existence of cells for the elabo- 



ration of lymph, similar to 



those described as existing in 



the intestinal villi. 



mi / i i 



The structure of the lym- 



Bloodvessels and .Lymphatics irom the iailoitne 



Tadpole. 



phatic vessels is like that of 

 the lacteals. They have the same number and character of coats; the 

 same crescentic valves or sphincters, occurring in pairs, and giving 

 them the knotted and irregular appearance, for which they are remark- 

 able; every contraction indicating the presence of a pair of valves, or 

 sphincter. The minutest lymphatics seem, however, to be destitute of 

 valves : but they are discernible in those of less than one-third of a line 

 in diameter, and have the same structure as those of the veins. In 

 man, each lymphatic, before reaching the venous system, passes through 

 a lymphatic gland or ganglion, formerly called a conglobate gland. 

 These organs are extremely numerous; and in shape, structure, and 

 probably in function, resemble entirely the mesenteric glands. They, 

 therefore, do not demand distinct notice. They exist more particularly 

 in the axillae, neck, neighbourhood of the lower jaw, beneath the skin 

 of the nape of the neck, in the groins, and pelvis in the neighbourhood 

 of the great vessels. The connexion between the lymphatics and those 



1 See, on both sides of this subject, Mailer's Handbuch, u. s. w., Baly's translation, p. 273, 

 Lond., 1838; and Weber's Hildebrandt's Handbuch der Anatomic, iii. 113, Braunschweig, 

 1831. 2 Precis, &c., ii. 194. 



3 Manual of Physiology, Amer. edit., p. 205, Philad., 1849. 



