124 Chapter V 



[132] anticytase, the injection of specific guinea-pig's serum and that of 

 normal guinea-pig's serum should produce the same result, that is 

 to say the serums of castrated rabbits, when treated by these two 

 kinds of guinea-pig's serum, should exhibit the same antispermotoxic 

 power. Experiments have, however, proved that this is not the case. 

 The serum of castrated rabbits that have been injected several times 

 with normal guinea-pig's serum becomes distinctly autispermotoxic, 

 but its power to protect the spermatozoa of the rabbit against 

 being deprived of motility by the guinea-pig's spermotoxin is greatly 

 inferior to that which is developed in the serum of other castrated 

 rabbits that I injected with spermotoxic guinea-pig's serum. Of 

 course all the other conditions of the experiment were the same 

 for the two groups of rabbits. 



Several series of facts, then, focus to this fundamental point, that 

 the organism of an animal that has been deprived of its male sexual 

 organs is in a condition to produce antispermofixative. Against the 

 argument that we have drawn from the fact that the antispermotoxic 

 serum of castrated rabbits that have been treated with spermotoxic 

 serum acts without being heated, might be cited certain experiments 

 made by Ehrlich and Morgenroth. The antispermotoxic action in this 

 case, as already stated, demonstrates that the serum of prepared 

 rabbits contains antifixative. Otherwise, had the fixative not been 

 neutralised, it would have allowed the macrocytase of the rabbit's 

 serum to arrest the movements of the spermatozoa. Now the two 

 above-named observers have demonstrated 1 that the injection of 

 different serums into animals is capable of exciting in their blood the 

 development of anticytases. The macrocytase of castrated rabbits 

 which, before treatment with the spermotoxin, was capable of arresting 

 the movements of rabbits' spermatozoa acted upon by a fixative, 

 might become inert after the injections of spermotoxic serum of 

 guinea-pigs. To clear up this point I asked M. Weichardt 2 , who has 

 carried out work on this subject in my laboratory, to try by means 

 of unheated serums of normal animals, to restore the activity of 

 spermotoxin that had been mixed with antispermotoxic serum. Sper- 

 matozoa of rabbits were put into a definite mixture of spermotoxic 

 guinea-pig's serum, heated to 56 C., and antispermotoxic serum, also 

 heated to 56 C., obtained from castrated rabbits that had been treated 

 with spermotoxin. The spermatozoa remained very active in this 



1 Bert. klin. Wchnschr., 1901, S. 255. 



2 Ann. de TInst, Pasteur, Paris, 1901, t. xv, p. 833. 



