Page:Defensive Ferments of the Animal Organism (3rd edition).djvu/78

Finally, we may, for the purpose of tracing peptolytic ferments in tissues, inject into the tissues peptones and polypeptides, which contain sparingly soluble amino-acids, and observe directly whether any amino-acids are set free.

In all these experiments the co-operation of micro-organisms was most carefully excluded, and there can be no doubt that these ferments belong to the tissues themselves. The same holds for ferments