ROLE OF INFLAMMATION 167 



these rabbits showed a positive reaction and 2 were refractory. 

 There was no relationship ])etween the local manifestations follow- 

 ing the preparatory injection and the severity of the reaction after 

 intraxenoiis injection. It is of considerable interest that according 

 to their findings the histological pictmes of all the animals, in- 

 cluding the refractory ones, were identical before the intraxenoiis 

 injection. 



Prior to the intravenous injection there were no special changes 

 observed in the epitheliinii. All layers of the skin tissue were defi- 

 nitely edematous and the collagenous fibers ^vere swollen. The 

 capillaries were either empty or filled with blood. The skin ar- 

 terioles were normal. These authors observed, however, platelet 

 thrombi of various sizes. The polymorphonuclear leucocytes 

 formed several layers around the vessel. The severe primary re- 

 actions observed by Kielanowski and Selzer may be accounted 

 for by the fact that filtrates of seven day old broth cultures of 

 B. coli were injected in large amounts (two sites 0.5 c.c. each) . 



In positive animals, following the intravenous injection, the 

 edema and leucocytic infiltration showed no increase. Tlie venous 

 thrombi formed after the intra\en()us injection completely filled 

 the lumina and the necrobiosis of the red blood cells was dehnite. 

 In the early stages (up to two hours after the second injection) in 

 addition to the typical changes described, a strong dilatation 

 of the capillaries was also demonstrable. This occurred in the 

 blood vessels situated perpendictdarly or obliquely to the super- 

 ficial layers of the skin. The endothelium ^vas flattened otit but no 

 changes were ofjserved. The nuclei ^vere irregtilarly f)ut intensely 

 stained with hematoxylin. Isolated petechiae were seen only in 

 the early stages. Hemorrhage occurred at first only in the upper 

 layers of the skin, i.e., in the papillary layer, btit later it Avas 

 possible to observe small hemorrhages in the striated muscle. 

 Petechiae were often circumscribed and clearly separated from the 

 surrounding tissues and the spaces were filled with red blood cells. 

 Kielanowski and Selzer maintain that the reaction seemed to 

 depend on sudden rupttire of blood vessels and increased perme- 

 ability of the capillaries. Also, the macroscopic picture of the phe- 

 nomenon, i.e., the sudden apj^earance of hemoi rhage ^vithout pre- 

 liminary swelling seemed to them to corroborate the hypothesis of 

 capillary rupttire as the cause of the reaction. They think that the 

 subsequent necrobiosis is dtie to a disturbance in the blood supply. 



