100 Chapter IV 



peritoneal cavity on the eve of the decisive experiment. Such injection 

 at once provokes phagolysis, which is then followed by an abundant 

 exudation of leucocytes. When, next day, a dose of red blood cor- 

 puscles of the goose (deprived of serum by centrifugalising) is 

 introduced into the peritoneal cavity thus prepared phagolysis is no 

 longer produced, or very feebly, and is of very short duration. 

 Under these conditions the solution of the red corpuscles by the 

 peritoneal fluid is reduced to a minimum, and in its place an ex- 

 tremely rapid and considerable ingestion of red corpuscles by the 

 macrophages may be observed. In order that the experiment may 

 be completely successful it is advisable to use goose's blood heated 

 to 37° C. or thereabouts for the injection. 



Even when the red corpuscles of the goose are introduced, not into 

 the peritoneal cavity but into the subcutaneous tissue of guinea-pigs 

 that have received several injections of goose's blood, we can easily 

 prevent the extracellular solution of the red corpuscles which takes 

 place, as already indicated, in the normal guinea-pig. As in this 

 [107] case the goose's serum which is mixed with the corpuscles contributes 

 to the haemolysis, it must be suppressed by centrifugalising the 

 defibrinated goose's blood and by washing the corpuscles with normal 

 saline solution. 



Collectively, the facts I have just described clearly indicate that 

 the phagocytes must be regarded as the source of the haemolytic 

 ferment. The macrocytase remains in the body of these cells so 

 long as they are in a normal condition ; but immediately they are 

 injured, in consequence of the sudden introduction of foreign sub- 

 stances into the peritoneal cavity, a portion of the macrocytase escapes 

 and acts on the red corpuscles as if it had been employed in vitro. 



As the conclusion I have just formulated is of fundamental 

 importance in the study of resorption and immunity it is necessary 

 to support it by as many arguments as possible. For this reason, 

 therefore, I feel obliged to draw the attention of the reader to another 

 example of the resorption of formed elements. 



We have already spoken of the resorption of spermatozoa in 

 the peritoneal cavity, and of the part played by the macrophages 

 in this phenomenon. As a result of this resorption, just as after 

 that of red blood corpuscles, the organism acquires new properties 

 of the same character. Ijandsteiuer^ and the writer ^ have shown 



1 Centralblf. Bakteriol. u. Parasitenk., V* Abt, Jena, 1899, Bd. xxv, S. 546. 



2 Ann. de VInst. Pasteur, Paris, 1899, t. xiii p. 738. 



