Page:Defensive Ferments of the Animal Organism (3rd edition).djvu/80

 decompositions. The blood plasma is unable, either in the majority of animals or in man, to produce decomposition of albumens, peptones, and polypeptides, at least not in any degree which can be demonstrated by available methods. The capacity for decomposing fats is also apparently absent in most cases. On the other hand, we often meet with assertions that the blood always has a diastatic action, i.e., the capacity for splitting complicated carbohydrates. Under normal conditions the blood plasma does not generally seem to be constructed for the reduction of complicated substances. Only in the l case of guinea-pigs do we find conditions that are undoubtedly exceptional; here the blood plasma shows other properties, and even under normal conditions can partly break down polypeptides which are not in the least acted upon by the blood plasma of other animals. The cause of this peculiar behaviour of the plasma in guinea-pigs cannot yet be explained. That the blood plasma in general is lacking in digestive powers must obviously be construed in the sense that, under normal conditions, substances which are out of harmony with the plasma, and require a quick chemical reduction, never have access to the blood.

As soon as these observations had been made it become possible to study the question, whether the blood plasma exhibits new properties in cases where substances that are out of harmony with the plasma,