THE RENEWAL OF THE LYMPH. 187 



allowed to go on for some hours the same proportions of 

 salt and sugar would be found in the solutions on each side 

 of the dividing membrane. 



The Renewal of the Lymph. Osmotic processes play a 

 great part in the nutritive processes of the body. The 

 lymph present in any organ gives up things to the cells 

 there and gets things from them; and so, although it may 

 have originally been tolerably like the liquid part or plasma 

 of the blood, it soon acquires a different chemical composi- 

 tion. Dialysis then commences between the lymph out- 

 side and the blood inside the capillaries, and the latter 

 gives up to the lymph new materials in place of those which j 

 it has lost, and takes from it the waste products which it / 

 has received from the tissues. When this blood, thus al- / 

 tered by exchanges with the lymph, gets again to the stom- 

 ach and intestines, having lost some food materials, it is 

 poorer in these than the richly supplied lymph around their 

 cells, and takes up a supply by dialysis from it. When it 

 reaches the excretory organs it has previously picked up a 

 quantity of waste matters, and loses these by dialysis to the ' 

 lymph there present, which is specially poor in such mat- 

 ters, since the excretory organs constantly deprive it of 

 them. In consequence of the different wants and wastes 

 of various cells, and of the same cells at different times, 

 the lymph must vary considerably in composition in various 

 organs of the body, and the blood flowing through them 

 will in consequence get and lose different things in differ- 

 How does the lymph in an organ come to differ chemically from 

 the blood plasma which supplied it? What results? What happens 

 when the blood thus changed reaches stomach or intestine ? What 

 when it reaches excretory organs ? Why does the lymph vary in 

 composition in different parts of the body ? How does this affect 

 the blood ? 



