An Experimental Study of Anti-anaphylaxis. 117 



anti-bodies from the serum. If these are supplied, an animal 

 passes directly into the anaphylactic condition again, and this 

 reversal could conceivably be repeatedly renewed. 



Conclusions. 



1. Guinea-pigs which have been rendered actively anaphylactic 

 by a preliminary injection of foreign proteid (horse serum, egg 

 albumen), and have then been made anti-anaphylactic by the 

 injection of a sub-lethal dose of this proteid, may be immediately 

 re-sensitized by the introduction of serum from a pig sensitized, 

 or one immunized to the same proteid. Death is then produced, 

 with typical anaphylactic symptoms by the intravenous injection 

 of an amount of this proteid which to normal pigs is non-toxic. 



2. Actively anti-anaphylactic pigs may be re-sentitized with 

 serum derived from a rabbit immunized against the same proteid. 



3. Passively sensitized pigs, rendered anti-anaphylactic by 

 the usual methods, can be re-sensitized by the re-introduction of 

 an immune serum. 



4. A pig simultaneously sensitized to two different foreign pro- 

 teids, may be rendered anti-anaphylactic to one of these by the 

 usual methods, while its sensitiveness to the other remains un- 

 impaired. This demonstrates that anti-anaphylaxis cannot be 

 due to exhaustion of complement, since complement is amply 

 present. 



5. The introduction of normal guinea-pig's serum into an 

 anti-anaphylactic animal fails to re-sensitize. Some factor other 

 than complement, therefore, must be introduced in re-sensitization. 



6. The absence of available anaphylactic antibodies appears 

 to be the cause of the refractory condition known as anti-ana- 

 phylaxis, and re-sensitization is due to their re-introduction. 



83 (692) 



The toxicity of foreign leucocytes. 

 By WILFRED H. MANWAEING. 



[From the Rockefeller Institute for Medical Research.] 



The injection of from 0.7 c.c. to 1.0 c.c. of rabbit leucocytes 

 into the cerebral meninges of dogs is apparently invariably fatal. 



