102 Chapter IV 



several hours. When, however, guinea-pigs have received one or 

 several injections of the spermatozoa of their own species, their serum 

 and peritoneal lymph become distinctly toxic and render the sperma- 

 tozoa motionless in a few minutes. In male guinea-pigs so prepared 

 the serum acquires this toxic property not only for the spermatozoa of 

 other male guinea-pigs, but likewise for those of the individual itself 

 which furnishes the serum. This latter, then, becomes distinctly 

 autospermotoxic. 



If the spermotoxin were diffused in the plasma and other fluids of 

 the guinea-pig which furnishes it, it ought to render motionless the 

 spermatozoa contained in the genital organs. Experiment demonstrates, 

 however, that this is not the case. If the male organs be removed 

 from a guinea-pig whose serum is very autospermotoxic in vitro, we 

 find, especially in the epididymis, a mass of very virile spermatozoa 

 which for a long time retain their motility in physiological salt 

 [109] solution. The macrocytase, then, has not reached the spermatozoa 

 in the living animal ; this is because it is not found in the plasmas. 

 Let us inject into a guinea-pig, whose serum is strongly autospermo- 

 toxic, one portion of sperm into the subcutaneous tissue and another 

 portion into the peritoneal cavity. In the first site a soft oedema, 

 filled with transuded fluid, in which the very active spermatozoa 

 retain their motility for a couple of hours, is produced. In the peri- 

 toneal fluid the same spermatozoa become motionless in a few 

 minutes. This great difference is explained by the fact that, under the 

 skin, there are no, or almost no pre-existing leucocytes, whilst in the 

 peritoneal fluid they are abundant. The phagocytes injured by the 

 introduction of sperm into the peritoneal cavity, abandon a portion of 

 their macrocytase, sufficient to render the spermatozoa motionless. 

 But when Metalnikoff injected physiological salt solution into the 

 peritoneal cavity of his autospermotoxic guinea-pigs, and then, on the 

 following day, a quantity of sperm, the spermatozoa continued very 

 active for more than an hour. In this case phagolysis is very transi- 

 tory and insignificant; it is soon followed by a great afflux of 

 leucocytes which bring about a rapid ingestioii of the spermatozoa. 

 Many of these elements are devoured in a living state ; for even when 

 their body is enclosed in the macrophage, their tail, left outside, 

 continues to move very actively. 



All these experiments demonstrate that in the normal state the 

 macrocytase remains within the phagocytes and only escapes during 

 phagolysis, or at the moment when the blood, after it has been with- 



