238 



Scientific Proceedings (115). 



in all were given to each guinea pig during the course of seven 

 weeks. The last injection was given November 29, 1920. We 

 attach considerable importance to the method of sensitization 

 which was similar to that found best in this laboratory in the case 

 of bacterial proteins. We did not rely on one or two sensitizing 

 injections, but injected every day for several weeks. 



The uteri of the three treated guinea pigs were tested by the 

 Dale method on December 22 and 23, 1920. The uteri of two 

 normal pigs were also tested. 3 c.c. of the pollen extract when 

 added to the bath of 200 c.c. Ringer's solution had no effect on 

 the normal uteri; while I or 2 c.c. of the same extract produced 

 marked contraction and prolonged spasm of the sensitized uteri. 

 In one instance, 3 c.c. completely desensitized one horn of a 

 sensitized uterus to the further instillation of 3 c.c. of pollen extract 

 into the bath. 



The extract added to the bath in the Experiment I was pre- 

 pared by extracting the pollen with 0.02 per cent. Na2COa, in- 

 stead of with 0.04 per cent. NaOH. 



The graphic record of this experiment is omitted because it is 

 in principle exactly like the record of Experiment II, which is 

 given below. 



In view of the fact that clinical observers, Cooke and Vander 

 Veer, were obtaining skin reactions with pollen extracts, the anti- 

 genic nature of which they, as well as Coca, denied, it was natural 

 to think of the possibility that our preparations might be funda- 

 mentally different from the ones they were using. It was of 

 course of great practical importance to determine whether or 

 not their preparation would fail to show antigenic properties if 

 tested by our methods. Accordingly, we obtained from Dr. 

 Cooke a specimen of the preparation of pollen actually used by 

 them on patients, and the sensitiveness of the guinea pigs sensitized 

 by the method described above, was then tested with this material. 



Experiment II. 

 Two female guinea pigs, No. 1121 and No. 1122 were sensitized 

 with Mulford high ragweed pollen extracted with 0.02 per cent. 

 Na 2 C0 3 solution. 36 c.c. in all, in doses of 2 c.c, were given to 

 each guinea pig in the course of 17 days. The last injection was 

 given on December 31, 1920. 



