252 ABSORPTION LYMPH AND CHYLE 



spaces communicate with the efferent vessels by stomata. The afferent 

 vessels, two to six in number, penetrate the gland and probably empty 

 their contents into the lymph-spaces. The lymph is then collected from 

 the lymph-spaces by the vasa efferentia, one to three in number, which 

 are always larger than the afferent vessels. 



The lymphatic glands are supplied with blood, sometimes by one 

 but usually by several small arteries, which penetrate at the hilum. 

 These vessels pass directly to the medullary portion and there break up 

 into several coarse branches to be distributed to the cortical substance, 

 where they ramify in a delicate capillary network, with rather wide 

 meshes, in the closed follicles of this portion of the gland. This capil- 

 lary plexus also receives branches from small arterial twigs which pene- 

 trate the capsule at different points. Returning on themselves in loops, 

 the vessels unite to form one or more large veins, which emerge usually 

 at the hilum. 



Very little is known regarding the distribution of nerves in the 

 lymphatic glands. A few filaments from the sympathetic system enter 

 with the arteries, but they have not been traced to their final distribution. 

 The entrance of filaments from the cerebro-spinal system has not been 

 demonstrated. 



The uses of the lymphatic glands are somewhat obscure. They are 

 supposed, however, to have an important office in the elaboration of the 

 corpuscular elements of the lymph and chyle ; and it has been observed 

 that the lymph contained in vessels that have not passed through glands 

 is relatively poor in corpuscles, while the large trunks and the efferent 

 vessels contain them in large numbers. 



Absorption of Proteids by tJie Lac teals. Comparative analyses of the 

 lymph and chyle show in the latter an excess of proteid constituents ; 

 and it is natural to infer that the excess of these matters in the 

 chyle is due to absorption of proteids from the intestinal canal. Lane 

 collected the chyle from the lacteals of a donkey, seven and a half hours 

 after a full meal of oats and beans, and compared its composition with 

 that of the lymph. The analyses were made by Rees, who found that 

 the chyle contained about three times as much albumin and fibrin as the 

 lymph. While by far the greatest part of the products of digestion of 

 proteids is absorbed by bloodvessels, there can be no doubt that a small 

 portion is also taken up by the lacteals. 



Absorption of Sugar and Salts by the Lacteals. Small quantities of 

 sugar and sometimes lactic acid have been detected in chyle from the 

 thoracic duct in the herbivora ; and the presence of sugar in both lymph 

 and chyle has also been observed. While the products of the digestion 

 of saccharine and amylaceous matters are taken up mainly by blood- 



