LECT. IV. ABSORPTION BY BLOOD-VESSELS. 83 



has confirmed the preceding conclusion. I feel bound to 

 cite here the principal results of the observations of our 

 countryman Panizza. 



There is no fact which demonstrates the existence of free 

 extremities in the ramifications of blood-vessels, which 

 everywhere present a very close and continuous reticulated 

 texture. The arterial network is uninterruptedly continuous 

 with the venous network which, in general, predominates 

 over the former. The lymphatic system, likewise, never 

 terminates by independent extremities, but every where 

 presents the aspect of a very fine and close trellis work. 

 Anatomy, which agrees with physiology, leads us to the 

 conclusion that the first part of absorption can be effected 

 ' only by the aid of the porosities proper to the structure of 

 organized beings. In this way the absorbed matters arrive 

 at, and mix with, the blood, the chyle, and the lymph, and 

 are carried away by these liquids, and distributed over the 

 body. 



Absorption by Blood- Vessels. I consider it now almost 

 superfluous to quote the experiments of Magendie, Segalas, 

 and the later ones of Panizza, all of which prove that ab- 

 sorption takes place principally by the intervention of the 

 blood-vessels. 



The following is the manner in which the last mentioned 

 physiologist proceeded : Having made an incision ten 

 inches long in the belly of a horse extended on the ground, 

 he drew out a fold of small intestine, in which arose several 

 small veins, which, after a short course, terminated in a 

 single very large mesenteric trunk, before any small veins 

 from the glands had emptied themselves into it. This fold, 

 nine inches in length, was tied by a double ligature in such 

 a manner that it could receive blood by a single artery only, 

 and could return none to the heart except through the ve- 

 nous trunk above described. An aperture was then made 



