146 



ANATOMY FOE NUESES. [CHAP. XII. 



it bathes, and we have two different fluids, separated by the 

 moist membrane which forms the walls of the blood-vessels, 

 the lymph in the tissues outside the walls of the capillaries 

 and the blood inside the capillary walls, and the same con- 

 ditions may be said to exist as in the salt and sugar solutions 



just spoken of. And now the same 

 phenomena take place; for though 

 the pressure is higher in the blood- 

 vessels than in the lymph outside, 

 some of the constituents of the lymph 

 pass into the blood by the process of 

 diffusion. 



These constituents, which, as we 

 cannot too often emphasize, are prod- 

 ucts resulting from the activity of 

 the tissues, are carried away by the 

 blood to other tissues, which will 

 either make use of them, or, as in 

 the kidneys, take them up to make 

 excretory fluids, and so remove them 

 from the body. 



In consequence of the different 

 wants and wastes of different tissues 

 at different times, both the lymph 

 and blood must vary in composition 

 in different parts of the body. But 

 the loss and gain is so fairly bal- 

 anced that the average composition 

 is pretty constantly maintained. The 

 blood, on account of the higher press- 

 ure, loses more liquid to the lymph 

 than it receives back, but this ex- 

 cess is returned back again to the 



FIG. 102. LYMPHATICS AND 

 LYMPHATIC GLANDS OF AXILLA blood by the lymphatics when they 



empty their contents into the veins. 



Lymphatic glands. 1 The lymphatic glands are small, solid 

 bodies, placed in the course of the lymphatics through which 



1 Lymph nodes is the more appropriate name for these structures, but the 

 term " lymphatic glands " being still so generally used, it has been thought best 

 for the present to retain it in the text. 



