104 Chapter IV 



exists, then, in all these cases a constant relation between the degree 

 of phagocytosis and the amount of the fixative produced. As this 

 fixative facilitates the access of the cytase to the cells and as the 

 resorption of these elements takes place specially in the macrophages, 

 we are bound to come to the conclusion that the fixative is a second 

 phagocytic ferment which is produced in abundance during the process 

 of intracellular digestion. Only, instead of remaining in the substance 

 of the phagocytes, this fixative is in part thrown out from these 

 elements. It passes into the plasma of the blood and into the other 

 fluids and ends by disappearing from the organism, probably being 

 eliminated by the excretory channels. 



In the Invertebrata, where, as we have seen, the alien red blood 

 corpuscles are also digested within the phagocytes, we have never 

 been able to demonstrate any haemolytic property of the blood fluid, 

 even after repeated injections of blood. We must conclude from this 

 [111] that in these animals the quantity of fixative is merely sufficient to 

 bring about the solution of the red corpuscles which are within the 

 phagocytes. In the case of fishes and higher animals (we may recall 

 the example of the red corpuscles of the guinea-pig when resorbed 

 into the organism of the gold-fish) the production of the fixative is 

 much more abundant, and this ferment can be easily demonstrated by 

 its action in vitro. 



This over-production of a ferment which acts in the phagocytic 

 resorption, finds its analogue in the passage of certain digestive 

 ferments, such as amylase and pepsin in man and the dog, into the 

 blood and urine, as mentioned in the preceding chapter. 



One of the best arguments in favour of the thesis here developed, 

 has been furnished to us by the analysis of the phenomena observed 

 in connection with the autospermotoxic serums of the guinea-pig. 

 This idea of autotoxins was originally put forward by Ehrlich in his 

 memoirs, published in conjunction with Morgenroth and already 

 repeatedly cited. Ehrlich asked himself whether the organism which 

 resorbs, not red corpuscles of an alien species, but red corpuscles of 

 its own species, would also be capable of developing haemolytic 

 substances. With this object he injected blood obtained from goats 

 into these same goats or into other individuals of the same species. 

 He and Morgenroth^ were, under these conditions, able to obtain 

 isotoxic serums, that is to say serums which dissolve the red corpuscles 

 of the goat, coming from other individuals than those which had been 

 1 Berl. Jdin, Wchnschr., 1900, S. 453. 



