3O DEFENSIVE FERMENTS OF THE ANIMAL ORGANISM 



especially the lestes, approach maturity, replaced by 

 protamines, which consist nearly exclusively of di- 

 amino-acicls. \Ve see, in this example, how cells of a 

 characteristic structure transfer their material to the 

 blood circulation in a profoundly modified form. 

 First of all substances are produced that are in 

 harmony with the plasma, and these are transferred 

 to the cells of the sexual glands by means of the cir- 

 culation. These glands take up the indifferent 

 substances, and from them build up products specific 

 to themselves. There is no doubt that similar pro- 

 cesses play a part in normal metabolism. Sometimes 

 one group of cells will help another in this way, par- 

 ticularly in cases where the supply of nourishment is 

 delayed for some time. 



The reconstruction of substances of every kind 

 from products that are harmonious to the plasma and 

 the lymph is demonstrated by every growing hair and 

 every growing nail. Every new blood corpuscle tells 

 us of far-reaching transformations ; and every secre- 

 tion whether produced directly, as in the case of 

 saliva or milk, or manifested when a fistula is pro- 

 duced by surgical means, or whether it forms a 

 so-called internal secretion, choosing the blood or the 

 lymph for its path of action every one of these gives 

 evidence of powerful disintegrations, integrations, or 

 transformations. When thousands and thousands of 

 leucocytes hurry forth against an invasion of 



