SIGNIFICANCE OF PHENOMENON 381 



seem to express themsehes in (1) combined severe vascular dam- 

 age, inflammation, and necrosis at the sites of highest reactivity 

 with (2) subsequent repercussion ot this reaction upon the blood 



I'lfi. 3.S. 5. Histologic appearance ot petechial hemorrhages at b. Note siib- 

 c])iclerinal capillary hemorrhage, riirombosis absent. (Shwart/man, Klemperer and 

 (.cri)er. 1936.) 



\essels distant from it, manifestino itself in altered vascular re- 

 sj3onse ^vith the formation of thrombi. The findings, therefore, 

 offer a basis for the experimental demonstration of conditions of 

 licmorrhagic diathesis, the mechanism of ^vhich essentially con- 

 sists of the following distinct phases: 



Elicitation of a latent vascular reactivity folloA\ed by the pro- 

 duction of local vascular lesions ^vhen certain reacting factors 

 are superimposed at suitable times, and an incidental effect of the 

 local lesion upon distant capillaries which leads to a tendency to 

 thrombosis and to other expressions of altered vascular response 

 (capillary "toxicosis," i.e., hemorrhage follo^ving mechanical or 

 other injury) . 



As previously mentioned, while the state of reactivity can be 

 elicited exclusi\'ely by certain bacterial principles, potent provoc- 

 ati\e factors may be obtained not only from bacteria but from 

 combinations of animal proteins ^vith homologous antibodies. 

 Thus, it is possible to fit into the experimental findings presented, 

 at least in the form of a ^vorking hyjsothesis, the two major groups 

 of hemorrhagic diathesis, namely: 



Symptomatic pinpura of infectious diseases in ^vhich bacterial 

 factors alone may be implicated in the production of all the 

 jihases; and the so-called "anaphylactoid" conditions of hemor- 



