308 GENERAL ANATOMY. 



formed of roots, which collect themselves in the manner of 

 veins. In those of the members, for the distance of several 

 feet, there are no interruptions of this kind; in those of the 

 mesenteiy, every few lines there are glands. Some pass along 

 side of a gland without entering it. It would even appear, 

 according to Cruikshank, that the lymphatic vessels of the 

 back arrive at the trunk without meeting any glands; but 

 Mascagni, whose authority in these matters is so great, assures 

 us that no lymphatic vessel reaches the trunk, unless it has 

 passed at least through one gland. 



466. After a course more or less long, more or less inter- 

 rupted by ganglions, the lymphatic vessels of the inferior half 

 and of the superior and left quarter of the body, terminate by 

 a very elongated trunk, the thoracic duct, into the left subcla- 

 vian vein; the others terminate by a very short trunk in the 

 other subclavian vein. These modes of terminations are them- 

 selves subject to different variations. Does there exist other 

 terminations of the lymphatic vessels in the veins? A part of 

 this query must be examined here, and the other when we 

 shall speak of the lymphatic ganglia. 



Several anatomists and physiologists have admitted this 

 opinion,* which may be founded on the circumstances that 

 every where, and especially in the mesentery, the known ra- 

 dicles of the lymphatic vessels have a capacity much greater 

 than that of the vessels which form their continuation; on the 

 circumstance that in this part of the body, also, there is often 

 found in the veins, as in the lymphatic vessels, substances in- 

 troduced by absorption, and even those which have been 

 directly injected into these latter vessels; and finally, on 

 the circumstance that the mere tying of the thoracic duct, 

 causes death only after ten or fifteen days, and that the sub- 

 stances introduced into the intestines, and absorbed by its in- 

 ternal membrane, arc then found in the blood. But this com- 

 munication has never been seen, nor is it generally admitted. 

 It would appear to be especially in the lymphatic glands 

 that it occurs; but we shall revert to this subject hereafter, 

 (art. ii. ) 



* See Ludwig, be. cit. 



