Resorption of albuminoid fluids 125 



mixture which contains specific fixative (in the spermotoxic guinea- [133] 

 pig's serum) and antispermotoxiii. To this mixture is added a little 

 normal rabbit's or horse's serum, unheated. These serums contain 

 cytases and would be quite capable of arresting the movements of the 

 spermatozoa if there was found in the mixture any free fixative that 

 would enable the macrocytase to be linked to the spermatozoa. Under 

 these conditions the spermatozoa remain motile for a long time. The 

 fixative, then, was no longer active ; it was neutralised by the anti- 

 fixative of the antispermotoxic serum of castrated rabbits. A control 

 experiment was made with the same substances ; but the castrated 

 rabbits' serum that had been treated with spermotoxic serum was 

 replaced by the serum of other castrated rabbits treated with normal 

 guinea-pig's serum. In these latter mixtures the spermatozoa became 

 motionless at the end of a very short time ; the fixative, not being 

 neutralised, readily allowed the rabbit's and horse's cytases to affect 

 the spermatozoa. 



It follows from all this that the antispermotoxic serum of castrated 

 male rabbits, when treated with normal guinea-pig's serum, contains 

 anticytase only ; whilst the serum of castrated male rabbits, treated 

 with specific and spermotoxic guinea-pig's serum, contains anticytase 

 and antifixative. The latter, then, has been produced independently 

 of the sensitive elements, the spermatozoa. 



Having established the fact that antispermotoxin does not come 

 from the male organs, it was necessary to try to ascertain its true 

 source. With this object in view we injected spermotoxic serum into 

 young rabbits (quite capable of producing antispermotoxin) and tried 

 to follow the fate of the spermotoxin in the organism. When spermo- 

 toxic guinea-pigs serum is injected into the peritoneal cavity of the 

 rabbit a notable amount of spermotoxin is found in the thickened 

 portion of the omentum made up of lymphoid tissue. But the greater 

 portion of the poison passes into the circulation whence it goes to fix 

 itself in various organs, especially the spleen. At the moment when 

 the spermotoxin is found in the blood a certain quantity of this fluid 

 was drawn off into tubes containing some drops of extract of leeches' 

 heads. After the blood thus treated had been centrifugalised the 

 plasma was decanted and its power of arresting the movements of 

 spermatozoa was compared with that of serum of the same blood 

 prepared in the usual way. From these researches it results that the 

 plasma is always richer in spermotoxin than is the corresponding [134] 

 serum. Sometimes the difference in favour of the plasma is very great. 



