244 LOCAL TISSUE REyVClTIVITY 



tumor siu\i\C(l ior a j)r()l()n<4e(l j^ciiod. (()iiij)lcif healing cNciitu- 

 all)' took place. It may be safely stated tliat the iiuideiue ol 

 spoiitaiieotis regression observed ^vas far beyond normal ex- 



Tiny necrotic tumors in surviving mice. 



Growth 1+ and 2+ in surviving mice. 



i** = Growth 3+ and 4+ in surviving mice* 



Diagram 3. Effect ol spontaneous epidemics on .^lowlh ol' mouse sarcoma iSo. 



(Shwartzman, i936«.) 



pectancy. No definite conclusions may be dra^vn, ho^vever, con- 

 cerning the percentage of regression, since most of the infected 

 mice died Avithin the first month. The possibility still remains 

 that the timiors might have resumed their growth if the mice had 

 lived longer. 



Incidentally, it is of interest that the infection of the tumor 

 inoculinn ^vith B. enferitidis apparently played no role in the 

 development and the growth energy of the ttmior provided the 

 mice inoculated ^vere either free from, or innnune to the infec- 

 tion. Thus, a group of 30 mice ^vas inoculated ^vith material from 

 a tiunor infected ^vith B. eiileritidis and a group of 70 mice 



