1912.] Resistance to the Growth of Implanted Cancer. 



205 



3. 206/100 B. Mice 1—11 inoculated in right axilla, dose 0-03 c.c. 

 (11.12.11). Tumours excised (22.12.11), and the mice inoculated in 

 left axilla with 0'02 c.c. of 63/56 D (23.12.11). Mice 12—23 : control 

 to re-inoculation. 



2// 9// /6/I 



R. l. 1C~T /?. l: 



I f 13 $ 



4 f } e ! 



* \ 9 - ----- - - , 6 . I 



6 I I ,T : 



7 i f _ — _ — 18 9 



8 j j - — - — 19 8 



9 I j 20 f 



10 I I - - 21 • 



P W CM. 



Fig. 4. — Shows the induction of resistance by strain 206 in all mice. 



' Proceedings ' two years ago* It was then noted that, in a series 

 of mice inoculated with this strain, about one-third would show 

 progressively growing tumours, another third would show spontaneous 

 absorption after temporary growth of variable duration, whilst the remainder 

 would, after temporary cessation, resume the progressive type of growth. 

 It was also shown that there was an active resistance induced not only 

 in the cases where the tumours had undergone spontaneous absorption, 

 but also where they had temporarily ceased to enlarge their dimensions. 

 The strain still continues to manifest the type of growth observed in the 

 earlier generations. An analysis of the reaction set up by it in a series 

 of mice was attempted by excising the growths on a given day, and 



* Bashford, E. F., and Eussell, B. B. G., " Further Evidence on the Homogeneity of 

 the Besistance to the Implantation of Malignant New Growths," 'Boy. Soc. Proc.,' 1910, 

 B, vol. 82, p. 298. 



