REACTIVITY OF MALIGNANT NEOPLASMS 2^3 



hours after the intravenous injection. In man) instances the 

 hemorrhage extends finther t^venty-four hoins hiter. Beginning 

 witli the second day folloAving the injection, there is ohser\'ed 



Fig. 23. Section of tumor; X 220. Mouse bearing twelve day old sarcoma iSu re- 

 ceived 100 units of B. typhosus "agar washings" filtrate intravenously. Section shows 

 histologic appearance nineteen days after injection. Note area of granulation tissue. 

 No tumor cells are seen. (Shwartzman, 1936/).) 



formation of a dry liemorrhagic seal) ^vith a stirroiniding zone of 

 apparently active growth. About the sixth or seventh day, the 

 scab falls off leaving a bed of granulation tissue livhich, in many 

 instances, goes on to complete healing. It is of corrsiderable 

 interest that the zone of actively proliferating tumor tisstie seen 

 the first few days after the intravenous injection, may unexpect- 



