TBE LTSINS. 147 



it has greater affinity for the spermatozoon than it has for the blood 

 corpuscle. Furthermore, it was observed that when immune serum 

 obtained from a rabbit treated with the spermatozoa of the ram was 

 mixed with the spermatozoa of the horse, allowed to stand, and cen- 

 trifuged, the supernatant fluid still manifested its hemolytic effect on 

 the erythrocytes of the ram. Moxter closed his paper with the fol- 

 lowing statements : 



(1) The immune body kills the spermatozoa within the animal 

 organism, but is inactive outside. There is no dissolution of the 

 spermatozoa. (2) The immune serum possesses a specific hemolytic 

 action on the red blood corpuscles of the ram ; it combines with 

 both the spermatozoa and the erythrocytes, but with the former with 

 greater avidity, (3) The immune serum has a marked specific ag- 

 glutinating action on the spermotozoa of the ram. (4) The erythro- 

 cytes of the ram are also agglutinated by the immune serum. 

 This action, however, can be observed only when the hemolytic sub- 

 stance has been rendered inactive. (5) The serum of a normal rab- 

 bit also kills the spermatozoa of the ram, but acts less rapidly and 

 less energetically than immune serum. The spermatocidal constitu- 

 ent of normal serum is identical with the hemolytic. 



Metalnikoff* has made an important contribution to our knowl- 

 edge not only of spermotoxins, but of cytotoxins in general. In 

 some particulars his investigations contradict those of Moxter. 

 The following is a condensed statement of his results : If a rabbit 

 be treated with a mixture of the spermatozoa and the defibrinated 

 blood of a guinea-pig, the serum of the former animal will be found 

 to be possessed of marked spermotoxic and hemolytic action. This 

 serum is divided into two portions, numbers 1 and 2. To No. 1 

 there is added a large quantity of red corpuscles ; the mixture is 

 allowed to stand at 37° for two hours and then centrifiiged. The 

 supernatant fluid does not dissolve more corpuscles when added even 

 after the addition of more alexin in the form of the serum of a 

 normal guinea-pig. This shows that all of the hemotoxic sensitizer 

 (intermediary body) is fixed, but it immobilizes spermatozoa as read- 

 ily as it did before it was saturated with red globules. This shows 

 that the spermotoxic sensitizer remains intact in the serum and 

 is not combined with the red corpuscles. To portion No. 2 of 

 the serum there is added an excess of spermatozoa ; the mixture 

 is allowed to stand for two hours at 37° and is then centri- 

 fuged. The supernatant fluid obtained in this case has neither sper- 

 motoxic nor hemolytic action. This shows that the spermatozoa have 

 combined with not only the spermotoxic sensitizer, but also with 

 the hemotoxic. While the red corpuscles fixed only the hemotoxic 

 sensitizer, the spermatozoa fixed both sensitizers. These investiga- 

 tions show that Moxter fell into error when he concluded that the 

 • Annates de Pl-nsiUut Pasteur, 1900. 



