IMMUNOLOGICAL RELATIONSHIPS 339 



rabbits). Undiluted and various dilutions of these sera (1:10, 

 1:100, and 1:1000) were injected intradermally. Single intrave- 

 nous injections of potent B. tyj)liosus culture filtrates were given 

 either t^vo, fi\'e, or t^venty-four hours after the skin injections. 

 No skin reactions follo^ved the intra\enous injection of the bac- 

 terial filtrates. 



Gratia and Linz (1933) , hoAvever, reported the follo^ving ex- 

 periments: 



A sterile sponge soaked in B. coli culture filtrate ^vas intro- 

 duced subcutaneously into the abdominal wall of rabbits. 

 T^venty-six hours later, ^vhen the skin appeared infiltrated and 

 edematous, the sponge ^vas removed, squeezed and the exudate 

 injected intracutaneously into the normal rabbit's ear. Two to 

 six hours later, an injection was made through the marginal vein 

 of the non-injected ear in a dose of 1 c.c. per kilo of body Aveight. 

 There appeared hemorrhagic reactions in the skin of the pre- 

 pared ears in 30 to 50 per cent of rabbits. In a subsequent pub- 

 lication, Gratia and Linz (1931c) themselves raised objections to 

 their experiments on passive transfer by means of the sponge. 

 This time in their control experiments on the minimum incuba- 

 tion period necessary for the elicitation of the phenomenon of 

 local skin reactivity Gratia and Linz found that even after an 

 interval of time as short as five hours following the injection of 

 the toxic filtrate alone, it is possible to produce the necessary 

 state of reactivity. Inasmuch as in the sponge experiments the 

 sponge juice unquestionably contained some of the bacterial 

 filtrates in which the sponge ^vas soaked, Gratia and Linz agreed 

 that their experiments are not indicative of passive transfer. More- 

 over, in my early studies I reported that twenty-four hours was 

 the optimum interval between skin-preparatory and intra\'enous 

 injections, but I also stated that reactions were obtained in some 

 rabbits if the interval of time was considerably shorter (eight 

 hours and less) . 



Bock (1932) also reported on his failure to accomplish a pas- 

 sive transfer of local skin reactivity. This author used for passi\e 

 transfer serum and defibrinated blood from animals ^vhich were 

 positive for the phenomenon and also serum of prepared rab- 

 bits before the provocative injection ^vas given. Lack of passive 

 transfer Avas further confirmed by H. Gross, Plaut, P Bordet, 

 Witebsky, Michelazzi and Alechinsky. 



