CI1YLIFEROUS SYSTEM. 42J 



the other to the mesocolon. In the quadrumanous animals, 

 as in man, they are spread at a greater distance from each 

 other, and more equally, over the mesentery, and in part 

 over the mesocolon. There are more than a hundred mesen- 

 teric glands on the human lacteals, and about a fourth part 

 of these belong to the colon; they are larger and more 

 crowded on the dorsal portion of the mesentery, and more 

 minute and dispersed towards its intestinal margin ; but 

 notwithstanding their greater number and development, their 

 uses are not more apparent here than in the simpler forms 

 of vertebrata. The receptaculum is still formed by the union 

 of the lacteal with the inferior lymphatic trunks, the primi- 

 tive reticulate structure and duplicity of the thoracic duct 

 is still perceptible in the frequent divisions presented in its 

 course, and it still terminates at the junction of the subcla- 

 vian with the jugular vein, as in most of the vertebrated 

 tribes. And thus the chyhferous system, though a mere 

 appendage to the venous, serving to convey nutriment to the 

 blood and performing functions assigned to the veins in the 

 lowest classes of animals, manifests the same laws of forma- 

 tion, and the same plan of perfection in the various grades of 

 its advancement, which we observe in all the more complex 

 parts of the economy, and appears like a remnant of the 

 simpler white-blooded sanguiferous system of the inverte- 

 brated tribes still on the march to a more isolated and com- 

 plete development. 



