126 Chapter V 



A part of the spermotoxin passes into the kidneys and the supra- 

 renal capsules. It is probable that, as is the case with so many soluble 

 poisons, a certain proportion of the spermotoxin may be eliminated 

 by the uropoietic organs. A small quantity of this poison is found 

 also in the male and female sexual glands of young non-castrated 

 rabbits. 



The search for some main centre of origin for the production of 

 antispermotoxin has as yet led to no positive result. The power of 

 arresting the movements of spermatozoa first appears in the blood 

 plasma, and it is this same fluid which, later, is more antispermotoxic 

 than is any organ. Amongst the tissues which fix spermotoxin the 

 genital organs play not the slightest part in the production of anti- 

 spermotoxin. The experiments with castrated rabbits afford sufficient 

 proof of this. On the other hand it becomes more and more probable 

 that the phagocytic system, disseminated in many organs, and especially 

 the leucocytes, furnish the antispermotoxic substance. The fixation 

 of the spermotoxin by the leucocytes of the blood, such as the cells of 

 the omentum and of the spleen, already offers us a valuable indication. 

 The absence of any particular organ that might have the monopoly of 

 fixing the spermotoxin and which should later be found charged with 

 a predominant amount of antispermotoxin also speaks in favour of the 

 phagocytic origin of this antitoxin. 



After a single intraperitoneal injection of spermotoxic guinea-pig's 

 serum into young rabbits, the blood of the latter is distinctly spermo- 

 toxic for several days ; later it becomes indifferent, but eight or ten 

 days after the commencement of the experiment the blood begins to 

 exhibit an antispermotoxic power. In these cases the plasma shows 

 itself more active than the serum. When the rabbits are killed at this 

 stage of commencing antitoxic production, it is found that an extract 

 of the organs is not antispermotoxic or only feebly so. In all cases this 

 power, when it exists, is more feeble than that of the blood fluid. The 

 results obtained with extracts of organs are not constant. Sometimes 

 the spleen possesses more antitoxic activity, whilst the liver, thymus, 

 omentum, lymphatic glands and genital glands exhibit none of this 

 property. In other cases the survival of the spermatozoa that are 

 [135] influenced by the spermotoxin has been longest in the extract of the 

 suprarenal capsules. Sometimes the extract of the omentum exhibits 

 the greatest antispermotoxic power. This great variability in the 

 development of the property of protecting the spermatozoa accords 

 well with the idea that the elements which produce antispermotoxin 



