2O DEFENSIVE FERMENTS OF THE ANIMAL ORGANISM 



to regulate its own structure. The components of 

 the blood plasma, which serve as the deriving material, 

 are the same for all cells. The formation of a speci- 

 fically acting secretion also requires that every kind 

 of cell should have means and arrangements at its 

 disposal for the specific transformation, under certain 

 circumstances, of the same product. From this 

 point of view we should expect to find that 

 each kind of cell controls particular ferments, 

 of which, however, some will be common to all 

 the cells of the body. These ferments have 

 the task of decomposing the nourishment, brought 

 by the blood plasma to the cell, into simpler 

 products. Investigations on the peculiarities of 

 cell ferments the tools of the cells are already in 

 progress, and we shall deal with this question later 

 on. It may be that the result of these investigations 

 will supply the most unequivocal and sure support 

 for the theory of the dependence of cellular function 

 on cellular structure. 



For the maintenance of a regular and undisturbed 

 flow in the varied processes of the cell, we must 

 assume that within certain limits constant conditions 

 prevail. When we carry out certain experiments in 

 a laboratory and try to study, for instance, the inter- 

 action of two substances upon each other, we choose 

 the most favourable conditions possible, and take 

 particular precautions against the presence of any 



