156 



Scientific Proceedings (84). 



93 (1271) 



Immunization against cyanolophia. 



By Rhoda Erdmann. 



[From the Osborn Zoological Laboratory of Yale University, New 



Haven, Conn.] 



When in June, 1915, I was introduced to the study of Cyano- 

 lophia by A. von Wassermann, Berlin, I performed, under his 

 guidance, several series of experiments to immunize against this 

 chicken disease caused by a filtrable virus. We tried to establish 

 active immunity by treating the animals with attenuated inocu- 

 lated brain, attenuated inoculated liver, attenuated serum in- 

 oculated into bone marrow and virulent sera of different ages 

 and different strengths. The attenuation was effected either by 

 "cultivating" the virulent tissues in chicken plasma after the 

 tissue culture method or by weakening the virulent serum by 

 "cultivation" in bone marrow and chicken plasma. Our tenta- 

 tive experiments, from June, 1915, to October, 1915, did not give 

 results. Only one chicken resisted an inoculation of virulent 

 brain after the following treatment. This chicken, No. 13, had 

 received two inoculations with serum which was obtained 17 

 hours after the inoculation of virulent brain into another animal. 

 We applied one inoculation with attenuated brain tissue and 

 later bone marrow with attenuated serum was implanted under 

 the skin. After a short interval this animal received another 

 serum treatment and then two days later a lethal dose of virulent 

 brain. It survived this strongest test, while a control chicken 

 which was inoculated with the same brain, but had not undergone 

 these different treatments, died in due time. The immunity of 

 No. 13 was gained without intention. Owing to the scarcity of 

 chickens to be used for experimental purposes at this time in 

 Germany, we had always used the same chickens for our experi- 

 ments, after the preceding inoculations with the different attenu- 

 ated materials proved ineffective. So we did not expect No. 13 

 to live after we inoculated it with virulent brain. We intended it 

 to die for affording virulent serum. As closely as possible we 

 repeated the same treatment, which we had applied to No. 13 



