Resorption of the formed elements 103 



drawn from the organism, coagulates. Is it the same for the fixative ? 

 It is easy to prove that this soluble ferment circulates in the plasmas 

 of the living organism. We have already said that the spermatozoa 

 of a guinea-pig whose serum is very autospermotoxic, remain alive for 

 some time in the physiological salt solution. But if we introduce 

 them, in vitro, into the serum of a normal guinea-pig they remain 

 motile but a short time (some 10 20 minutes), whilst the spermatozoa 

 of a normal guinea-pig will live in the same serum for several hours. 

 This difference is explained by the fact that the spermatozoa of the 

 autospermotoxic guinea-pig, although very active, have absorbed 

 the fixative during the life of the animal. This fixative is, as we 

 have stated, found in the body fluids and has been able to penetrate 

 to the male organs. Here the spermatozoa become charged with 

 the fixative and, once transported into the serum of the normal [no] 

 guinea-pig, rich in macrocytase, they lose their movements very 

 quickly. At the same time the spermatozoa used for control, not 

 having absorbed any fixative, are able to live for a long time in the 

 same serum. 



As the macrocytase remains fixed to the phagocytes there can be 

 no doubt as to its origin ; it is elaborated by these cells. Whence 

 however comes the fixative which is free in the body fluids and which 

 is precisely the substance that is developed in so large a quantity in 

 the treated animals ? The exact solution of this question is not easy ; 

 nevertheless there are many facts which indicate that this fixative is 

 also of phagocytic origin. We know already that the serums of normal 

 animals contain only small quantities or sometimes, perhaps, none of 

 the fixative. This fixative only appears abundantly as the result of 

 the resorption of the corresponding elements, red corpuscles or sper- 

 matozoa. This resorption, as we have said, is almost exclusively the 

 work of the macrophages. It is just in those cases where the red 

 corpuscles, injected into the peritoneal cavity of an animal of the same 

 species, pass directly into the lymph, without being injured or, save 

 exceptionally, ingested by the phagocytes, that the fixative is not 

 formed. When the red blood corpuscles of the goose, introduced with 

 defibrinated blood below the skin of a guinea-pig, undergo there a 

 partial solution in the fluid of the exudation, and where the phago- 

 cytosis is more limited than in the peritoneal cavity, the production of 

 fixative is small. When the injection of the same goose's blood is made 

 into the peritoneal cavity of a guinea-pig and is followed by complete 

 phagocytosis, the fixative is produced in greater abundance. There 



