2OO Hitman Physiology. 



expelled ; containing, in the waste and refuse of the animal body, 

 the richest food for the sustenance of the vegetable kingdom ; 

 which civilised men waste, polluting rivers, the sea, and the 

 atmosphere with matter, which, restored to the soil from which 

 it came, would yield them incalculable riches. 



One portion of the nutritive matter which has become 

 digested, and perhaps vitalised, in the stomach and small 

 intestines, is absorbed by the veins ; another portion is taken 

 up by a system of minute, transparent tubes called lymphatics. 



Fig- 43- LYMPHATICS OF SMALL INTESTINES. 

 The glands enlarged by disease. 



These form a curious network, gathering in little knots which 

 are called the lymphatic glands, and in these, under some 

 action of the nerves of organic life, the matter of food appears 

 to be transformed into blood ; for these vessels unite in a duct 

 which carries the lymph into a large vein, whence it goes 

 directly to the heart, and after being subjected to the action of 

 oxygen in the lungs, becomes red, arterial blood, and is circula- 

 ted through the entire body. 



Of the food received into the mouth, only a very small por- 



