

ABSORPTION BY THE LACTEALS. 285 



at different points. Returning on themselves in loops, the vessels unite to 

 form one or more large veins, which generally emerge 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 never been traced to their final distribution. The entrance of 

 filaments from the cerebro-spinal system has never been demonstrated. 



It is evident, from the structure of the lymphatic glands, that they must 

 materially retard the passage of the lymph toward the great trunks ; and it 

 is well known in pathology that morbid matters taken up by the absorbents 

 are frequently arrested and retained in the nearest glands. 



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

 posed, however, to have an important office in the elaboration of the corpus- 

 cular elements of the lymph and chyle ; and it has been observed that the 

 lymph contained in vessels which have passed through no glands is relatively 

 poor in corpuscles, while the large trunks and the efferent vessels contain 

 them in large numbers. 



Absorption of Albuminoids by the Lacteals. Comparative analyses of the 

 lymph and chyle always show in the latter fluid an excess of albuminoid 

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

 the chyle is due to absorption of albuminoids 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 Eees, who found that the chyle 

 contained about three times as much albumen and fibrin as the lymph. 

 While by far the greatest part of the products of digestion of the albuminoids 

 is absorbed by the blood-vessels, there can be no doubt that a small portion 

 is also taken up by the lacteals. 



Absorption of Glucose and Salts by the Lacteals. What has just been 

 stated regarding the absorption of albuminoids applies to saccharine matters 

 and the inorganic salts. Small quantities of sugar and sometimes lactic acid 

 have been detected in the chyle from the thoracic duct in the herbivora; and 

 the presence of sugar in both the lymph and the chyle has been determined 

 by Colin. While the products of the digestion of saccharine and amylaceous 

 matters are taken up mainly by the blood-vessels, a small quantity is also ab- 

 sorbed by the lacteals. In the comparative analyses of the chyle and lymph by 

 Rees, the proportion of inorganic salts was found to be considerably greater in 

 the chyle. The great excess in the quantity of blood coming from the intes- 

 tine, and the rapidity of its circulation, as compared with the chyle, will ex- 

 plain the more rapid penetration by endosmosis of the soluble products of di- 

 gestion. 



Absorption of Water by the Lacteals. There can be no doubt that a small 

 portion of the liquids taken as drink finds its way into the circulation by the 

 lacteals, although the greatest part passes directly into the blood-vessels. This 

 has been proved by experiments of a most positive character. When an ani- 

 mal has taken solid food only and is killed during digestion, the thoracic duct 

 contains a very small quantity of chyle ; but when the animal has taken liq- 

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