336 MATSUZIRO TAKENOUCHI 



the fact that the active immune chicken serum has slightly 

 higher hemolytic power than the normal chicken serum, that the 

 normal guinea-pig serum and the rat serum as well, with their 

 complements, cannot activate the hemolytic amboceptor in the 

 chicken immune serum to produce the hemolysis against rat 

 corpuscles. 



Serologically, this is an interesting fact when we recall that 

 some authors have used in cytolytic investigations chickens, 

 geese, and ducks as the serum producers. 



7. GENERAL DISCUSSION 



The attempt to get a strong antithymus serum from rabbits 

 by the injection of rat thymus gland seems to have failed en- 

 tirely. We are unable to verify Shimiau's results. His thymol- 

 ysin, according to his description, must have been able to do 

 more in vivo than the total removal of the thymus gland could, 

 because we know that the surgical removal of the thymus gland 

 can, if carefully done, be performed without any harmful effect 

 whatever. 



Moorhead ('05), reporting in a brief publication, says that his 

 "own experiments which, however, have not been completed 

 ('05), are so far entirely negative, although attempts have been 

 made to immunize rabbit against guinea-pig, guinea-pigs against 

 rabbit, and geese against guinea-pigs." He does not give any 

 details which would explain his negative results. 



We have tried to obtain a possible explanation of the negative 

 results of the serum action and have studied further the im- 

 munization of the rabbit against rat testis and rat corpuscles. 

 In the latter case we have learned that the hemolysin production 

 in the rabbit by the injection of rat corpuscles is very faint, and 

 more than that, the produced hemolysin is entirely incapable of 

 combining with normal rat complement to hemolyze rat cor- 

 puscles — a simple example of a well-known serological fact. 



If an analogy may be drawn between hemolysis and cytolosis 

 of other kinds, we are tempted to explain our failure in the pro- 

 duction of strong thymolysin when using the rabbit as a serum 

 producer and rat thymus as the antigen, in the same way as in 



