324 LOCAL riSSliE REACTIVITY 



in serum ol iiniminc animals; inadixity ol a variety ol non l)a(:- 

 terial substances; lailine of sodiinn carbonate to protect against 

 the phenomenon; and also on the absence of any relation between 

 the complement to the activity of the antigen-|-antibody com- 

 plexes. Although the possibility is not excluded that the j^roduc- 

 tion of reacting factors may be due to a mechanism somewhat 

 related to the j^roduction of anaphylatoxins, the present evi- 

 dence establishes no connection between the two. 



RELATION OF THE ACTIVE PRINCIPLES OF THE PHENOMENON TO 



FORSSMAN ANTIGEN-|-ANTIBODV COMBINATION AND 



NORMAL TOXICITY OF SERUM 



The following facts are quoted from reviews on the subject 

 by Davidsohn (1927) and l)y Doerr (1929). 



Forssman antibodies are hemolysins for sheep red blood cells 

 obtained ii{)on immunization of ral)bits with kidneys, suprarenals, 

 liver, testicle and brain of guinea pigs. Hemolysis cannot he 

 obtained l)y immunizing Avith red blood cells of guinea pigs. 

 Kidneys and suprarenals are of highest antigenicity. \Vhcn organs 

 of animals are capable of absorbing the hemolysins from the 

 rabbit hemolytic serum they are considered as belonging to the 

 guinea pig groups. These animals are: guinea pig, cat, horse, 

 tmtle, pigeon, dog, chicken, etc. Forssman antigen as found by 

 Schiff (1913) ill human red blood cells belonging to jansky's 

 Groups II and IV (receptors A and B) . On the other hand, coxv. 

 rabbit, eel, frog, goose, deer, rat, ox, etc. belong to the ralibit 

 group. Forssman hemolysins have some features in common ^vith 

 the iLSual anti-sheep hemolysins produced by the injection of 

 blood of sheep. They l)oth resist heating to 56° c. for one-half 

 hoiu' and are reactivated by addition of guinea pig complement. 

 Both are promptly absorloed by sheep red blood cells at o- c. 

 and 37° c. 



No direct attempts have been made as yet to study whether the 

 Forssman antigen -|-antibody combinations possess reacting po- 

 tency of the phenomenon. Although P. Bordet succeeded in elicit- 

 ing the phenomenon in prepared skin sites by intravenous injec- 

 tion of sheep red blood cells sensitized Avith anti-sheep hemolytic 

 rabbit serum, there is no evidence as yet Avhether sheep red 

 t3lood cells sensitized with sheep hemolysins obtained by immuni- 

 zation of rabbits with guinea pig organs Avotdd be equally en- 

 dowed with reacting potency. A priori, of coinse, it may be ad- 



