REACTIVITY OF MALIGNANT NEOPLASMS 247 



filtrate (T. i()t)<)) ol /». cnicritidis injected intravenously iii a dose of 1 c.c. 

 into mice bearing twelve day old tumors produced severe hemorrhagic lesions 

 in S mice (Fig. ^'i) and no effect in 2. 



Fig. 25. Histologic appearance of twehe dav old tumor twenty-four hours after 

 intravenous injection of li\c culture of rough B. ciiUn itidis. \'ial)le tiuiior tissue is 

 sharply demarcated \i\ zone of hemorrliage and necrosis. X 220. iMiw art/man, 

 iggGrt.) 



As is seen from the foregoing obser\ations, infections induced 

 \vitli B. enteritidis and injections of cidtiue filtrates of B. 

 elite) itidis exert a strong inhibitory inffiience on the development 

 of sarcoma icSo. Infections with Staphylococcus aureus and injec- 

 tions of ciiltme filti^ates of Stajjliyloeoceus aureus produce no effect 



