336 PHILOSOPHY OF ZOOLOGY. 



surface of which, numerous arteries terminated, and veins 

 originated. The orifices of these last were open. While 

 some of the lacteals terminated in these bags by numerous 

 orifices ; others formed merely a plexus on their walls, and 

 passed on with their contents to the thoracic duct. What 

 becomes of the chyle after it enters the bag? To this 

 question there is no satisfactory answer given, although it 

 appears probable that it passes directly into the surround- 

 ing open mouths of the veins. 



Besides the lacteals, there is another class of absorbents, 

 termed Lymphatics, whose contained fluid is a transparent 

 lymph. The office of these vessels is to collect the super- 

 fluous fluids from every part of the body, and to bring 

 them back again to the general circulation, either to be re- 

 novated, or thrown out of the system as useless. Hence it 

 is that the lymphatics take their rise in the skin, in the 

 mucous web immediately underneath the cuticle, in the in- 

 teguments of all the viscera, or wherever there is a part 

 subject to increase and diminution during life. The radi- 

 cles of the lymphatics unite into trunks, which are furnish- 

 ed with valves. They frequently anastomose, and enter 

 conglobate glands. They either empty their contents into 

 the thoracic duct, or pass on to one of the subclavian veins, 

 in which they terminate. 



Mr ABERNETHY, in the paper quoted above, has found 

 reason to conclude, that some of the conglobate glands of 

 the lymphatics of the horse are mere bags ; while others ap- 

 pear to have a cellular structure. These glands are libe- 

 rally supplied with arteries and veins. The effects which 

 they produce upon the lymph have not been determined, 

 although it is probable they are similar to those of the 

 mesenteric glands. Mr BRACY CLARK has found the trunk 

 of the lymphatic system of the horse to have several open- 

 ings into the lumbar veins. 



