Since Wolff-Eisner1 suggested in 1906 that the symptoms of pollen disease resemble the phenomena of experimental anaphylaxis, the relationship of these conditions has been extensively studied clinically and experimentally. Soon after 1906 Billard and Maltet,2 Meltzer3 and Billard4 suggested that there were certain clinical and laboratory similarities of these conditions, while many others submitted experimental evidence to support this view. Dunbar,5 Koessler,6 Heyl,7 Alexander,8 Harrison and Armstrong9 and Parker10 reported the demonstration of severe or fatal anaphylactic symptoms following the injection of pollen extracts into specifically sensitized guinea-pigs. Parker,11 using the uterine strip method, demonstrated that active sensitization of guinea-pigs with pollen extracts can be accomplished, an observation that was to be anticipated considering the protein content of pollens. Dunbar, Koessler and Alexander reported successful passive sensitization of normal guinea-pigs by injecting into them the blood serum of patients suffering from pollen disease or of guinea-pigs sensitized with pollen extracts.