ABSORPTION". 105 



pass through the ileo-caecal orifice into the large intestine, and there 

 become reduced to the condition of feces. 



The absorption of the digested fluids is accomplished both by 

 the bloodvessels and the lacteals. It was formerly supposed that 

 the lacteals were the only agents in this process ; but it has now 

 been long known that this opinion was erroneous, and that the 

 bloodvessels take at least an equal part in absorption, and are in 

 some respects the most active and important agents of the two. 

 Abundant experiments have demonstrated not only that soluble 

 substances introduced into the intestine may be soon afterward 

 detected in the blood of the portal vein, but that absorption takes 

 place more rapidly and abundantly by the bloodvessels than by 

 the lacteals. The most decisive of these experiments were those 

 performed by Panizza on the abdominal circulation. 1 This ob- 

 server opened the abdomen of a horse, and drew out a fold of the 

 small intestine, eight or nine inches in length (Fig. 40, a, a), which 



Fig. 40. 



c 



PAMZZA'S EXPERIMENT. 'in. Intestine, b. Point of lipatnre of inesenteric vein. c. Opening 

 in intestiue for introduction of poison, d. Opening in mesenteric vein behind tlie ligature. 



he included between two ligatures. A ligature was then placed (at 

 b) upon the mesenteric vein receiving the blood from this portion 

 of intestine; and, in order that the circulation might not be inter 

 rupted, an opening was made (at d) in the vein behind the ligature, 

 so that the blood brought by the mesenteric artery, after circulating 



1 In Matteucci's Lectures on the Physical Phenomena of Living Beings, Pereira's 

 edition, p. 83. 



