9 8 



Scientific Proceedings (91). 



chickens on vitamine-restricted diet. The fourth generation after 

 thirteen days' growth from February 12 to 25, 191 8, showed the 

 character of the original growth, especially the capacity to pene- 

 trate into the underlying tissues and to destroy them. 



I will not omit to point out that the growth described here 

 did not show bacterial contamination. The possible objection, 

 that this growth which is very similar to those described by Rous, 1 

 1910, a and b, and Rous and Lange, 2 1913 (compare I9i0 a , Fig. 5, 

 19106, Figs. 2 and 3, and 1913, Fig. 7) might be a "spontaneous 

 growth," I will refute immediately by saying that the repetition 

 of this series of experiments on a larger scale was successful. 

 Only in two of twelve chickens, which had received (1) implanta- 

 tion of heart tissue, (2) tetheline injections into the implant, (3) 

 vitamine-restricted diet, growths were produced, the other ten, 

 in which one or two different factors are lacking, showed no pro- 

 tuberance formation. 



The produced growth, the genesis of which I have outlined, 

 seems to be a connective tissue growth. It is infiltrable, destruc- 

 tive and transplantable. Further cytological investigation, espe- 

 cially the solution of the question, whether the implanted embry- 

 onic tissue cells are really forming by their descendants part of the 

 growth, will be necessary to name this transplantable growth 

 correctly. 



A detailed description of this growth and two others, together 

 with their descendants, will appear later. 



167 (1345) 



Immunization of monkeys against poliomyelitis. 



By H. L. Abramson (by invitation) . 



[From the Bureau of Laboratories Dept. of Health, N. Y. C] 



This work represents efforts made toward developing a prac- 

 ticable method of immunization against acute poliomyelitis. 

 Highly potent monkey polio virus is attenuated by heat in two 

 ways. In one case 5 c.c. of brain and cords in 10 per cent, saline 



1 Rous, Jour. Exp. Medicine, igio, p. 285 and p. 397. 

 * 1 Rous and Lange, ibidem, 1913, p. 651. 



