Abstract
Slices of spontaneous sarcomas of mice and Brown-Pearce carcinomas of rabbits were incubated with autologous liver slices to which were added heavy suspensions of investigated bacteria plus penicillin to suppress contaminant growth. Five microorganisms from which Sporosarcina ureae was selected for further study of 49 examined (including 3 trypano-somes) damaged tumor more perceptibly than liver. The evidence indicated cell material released on autolysis damaged tumor cells severely while having no effect on liver. Incubation was for 24 hrs. in an incubator shaker designed by Dub-noff. Slices were fixed in Bouin''s or Carnoy''s fluid, oriented in agar blocks, dehydrated and infiltrated with paraffin and subsequently sectioned parallel to the slice faces. Previous expts. with penicillin indicated that enormous dosages in vivo (50-100,000 units/diem/mouse) were necessary to damage tumor and no effect was perceptible due to the use of penicillin in 1000 units/ml. in these expts.