22 DEFENSIVE FERMENTS OF THE ANIMAL ORGANISM 



that it is at a quite definite stage that the by-products 

 of metabolism are passed by the cells into the lymph 

 channels, and so into the blood system. The indivi- 

 dual cell is in this sense responsible for the constant 

 composition of the contents of the blood, in the same 

 way as the cells of the bowels with their respective 

 ferments. 



Here, again, the animal organism controls im- 

 portant weapons of defence which may correct any 

 possible errors. Between the blood and the cells of 

 the body lies the lymph. The latter is the first to 

 receive the substances supplied by the individual 

 cells, and controls them by means of its accessory 

 apparatus, namely, the lymph cells and the glands. 

 Some of the substances are further disintegrated or 

 transformed in some other way, and, perhaps, even 

 utilized for various syntheses. From this point of 

 view we may look upon the lymph as a powerful 

 means of defence, whose aid is particularly valuable 

 in preventing the infusion into the blood of com- 

 pounds that are both quantitatively and qualitatively 

 unsuitable. From all sides care is taken that only 

 normally suitable substances shall appear in the 

 blood. 



From this point of view we may distinguish 

 substances that are " out of harmony with the body,'* 

 i.e., such compounds as, in their structure and 

 configuration, show no correspondence with the con- 



