ABSORPTION. 93 



produced by the gastric juice. In consequence of this 

 new action upon the chyme, in passing through the small 

 intestine, it is separated into a fluid of a whitish color named 

 chyle, which as soon as it is formed, is absorbed by the 

 radicles of a special system of vessels named chiliferous 

 vessels or lacteals; these reunite into branches more or 

 less voluminous, and ultimately meet in a common trunk 

 called the thoracic duct. This duct, which is about the 

 size of a common quill, conveys the chyle to its point of 

 junction with the sub-clavian vein at the lower part of the 

 neck, pouring it into the torrent of the circulation. Res- 

 piration gives to the fluid thus mingled with the blood its 

 finishing change, so that the two become identical. The 

 blood thus enriched, is spread through every part of the 

 body both external and internal, by means of the capil- 

 laries interjacent between the arterial and venous ramifica- 

 tions, thus furnishing to the system the necessary supply 

 of nutrient matter. 



The absorption of food into the organism is, therefore, 

 in principle, precisely the same in animals as in plants, with 

 this difference, that there is superadded to the organism 

 a highly complicated nervo-muscular apparatus for its pre- 

 hension and preparation. The introduction of food into the 

 digestive cavity or stomach, is wholly a voluntary act, and 

 results from the exercise of the functions of animal life ; 

 its digestion and absorption when there, is altogether in- 

 voluntary. The whole process of chymification and lacteal 

 absorption proceeds without our consciousness, and cannot 

 be controlled by any effort of our will. All these internal 

 motions are therefore purely vegetative acts, proceeding 

 from the operation of that life which we possess in common 

 with plants. 



This truth will be more apparent if the reader will only 



