338 MATSUZIRO TAKENOUCHI 



duce a true cytolysis in vivo. In such a case the result from 

 the serum injection cannot be attributed to the thymolytic 

 action only. In this connection we recall also the work of 

 Ritchie, who obtained a serum which contained a 'leucophilic 

 immune body/ by the immunization of ducks with the thymus 

 gland of guinea-pigs. Further discussion regarding Ritchie's 

 work is given later. 



So long as we are unable to obtain a more solid foundation, 

 we cannot accept the specific action of the antithymus serum, 

 nor, furthermore, can we believe any endocrine function what- 

 ever of the thymus gland, no matter whether the cortical or 

 medullary portion play the principle role in the physiological 

 function of this gland. 



So far as our results go, the chicken is not suitable as a serum 

 producer after injection of rat material. We should not try to 

 get the antithymus chicken serum because the hope of getting a 

 strong antiserum is very small, and even more than that, the 

 antithymus amboceptor produced may be incapable of causing 

 complete cytolysis (thymolysis) in vivo, by the reason of in- 

 ability of rat complement to activate the antithymus amboceptor. 



We ought to recall here the report of Ritchie ('08) and a quite 

 recent publication of Guyer and Smith ('18). The former used 

 ducks, as already stated, for the antiserum producer and injected 

 with the thymus of guinea-pig. 



The antithymus serum obtained did not show any specific 

 action in vivo, but fixed guinea-pig complement with the ex- 

 tract of thymus, lymph glands, and spleen. He concludes 

 from his experiment that the antithymus serum from ducks 

 contains a 'leucophilic body,' and not a specific thymolytic one; 

 the structural changes in the thymus of guinea-pigs following 

 injection of this serum were due to the 'leucophylic' action and 

 were not specific. The later authors produced an antilens serum 

 from chickens by the injection of the lens of rabbit or lens of 

 Peromyscus maniculatus gambeli. 



Though we have no right to cast doubt upon the validity of 

 their conclusions, we venture to question whether the comple- 

 ment of guinea-pig (Ritchie) and of rabbit and Peromyscus 



