METHODS OF ELICITATION OF PHENOMENON 205 



emic. The appearance of the heniorrhaoe and hy]KMj)lasia suo- 

 oested to them a capillary iragility. 



In Gerber's experiments animals were divided into two series. 

 One. consisting of 29 rabbits, received two intravenous injections 

 of bacterial filtrate six, twenty-four, or forty-eight hours apart. 

 The second, consisting of 35 rabbits, received an intradermal in- 

 jection of bacterial filtrate six. twenty-four hours or immediately 

 preceding the first intravenous injection; the second intra\enous 

 injection was given twenty-four hotns later. 



Of the 29 animals of the fust series, 20 (69 per cent) showed 

 venous thrombi in one or more organs. The lungs, liver and 

 spleen were affected 11. 14, and 9 times, respectively. Renal alter- 

 ations were observed in two animals. Adrenal necrc:>sis was not 

 observed. 



Twenty-nine (82.8 per cent) of the 35 rabbits of the second 

 series sho^sed venous thrombi in one or more organs. The lungs, 

 liver, and spleen were involved 19, 23, and 25 times, respectively. 

 Renal lesions occinred 5 times. Adrenal necrosis was found in 5 

 instances. 



The incidence of positive skin reactions, exclusive of those 

 which ^vere not read because of postmortem discoloration of the 

 skin site, was approximately 90 per cent. Only three animals 

 responded ^vith negative skin reactions. Venous thrombi were 

 fotnid only once in the spleen of one of the three animals. It is 

 not possible to conclude from this small series whether or not 

 failure of elicitation of the phenomenon of local skin reactivity 

 to bacterial filtrates can be considered as an indicator of the 

 resistance of the animals to the generalized effect of intravenously 

 administered filtrates. 



In studying the effect of the active principles of the phenome- 

 non upon the kidneys it ^vas necessary to exclude spontaneous 

 lesions in an exaluation of the effects of the injected bacterial 

 filtrates. Gerber was able to recognize spontaneous renal lesions 

 in the gross by diffuse cortical scarring. Such scars on histological 

 examination showed local interstitial round cell infiltration, in- 

 crease in connecti\e tissue and glomerular and tubular atrophy. 

 These lesions seen both in control and experimental animals Avere 

 identical with those described by Bell and Hartzell (1919), 

 Ophiils (1910-11), and others. In agreement with Apitz, Gerber 

 also found that the pathological changes in the kidneys resulting 

 from two injections of the active principles twenty-four hours 



