CHAPTBE VII. 



THE BLOOD AND LYMPH. 



The discussion of the taking in of food left that food 

 in a condition favorable for carriage by the blood, in fact, 

 as soon as the food material has passed through the mem- 

 branes (whether walls of blood vessels or walls of intes- 

 tines) into the blood stream such food was said to be 

 absorbed, or absorption had taken place. This absorp- 

 tion had, however, all taken place within a compara- 

 tively small area, therefore, unless this prepared food 

 was distributed through the body it would be of com- 

 paratively little use. The selection and use of the food 

 brought by the blood to various parts goes on in those 

 parts, the waste has to be removed also or disease would 

 result. In order for the blood to go to and return from 

 the tissues, roads must be provided — arteries and veins — 

 the motive power sending the blood to different points 

 being supplied by a powerful muscle pump — the heart. 

 The lymphatic or absorbent system, consisting of nodes 

 and vessels, whose function is to collect not only the nu- 

 tritive material by means of the lacteals of the intestines, 

 but also to gather up the waste material, all of which 

 they empty into the blood stream near the heart will be 

 considered as part of the circulation, in fact, owing to 

 the color of the fluid they carry, more or less milky in 

 the lacteals and colorless in other parts, it has been 

 dubbed the white blood system. Blood has two distinct 



