POLLANTIN. 427 



negative results in 11 per cent, of the cases. In 

 autumnal catarrh, 70 per cent, were positive, 19 

 per cent, partially positive, and 11 per cent, nega- 

 tive. 



The small bottles of antitoxin are accompanied 

 by a pipette with which from one to several drops 

 may be instilled into the eye or the nose. 



The serum does not cure permanently and one 

 who is susceptible should carry a vial for imme- 

 diate use during the hay-fever season. Repeated 

 use of this serum has been observed to result in 

 sensitization of the patient to horse serum. Dun- 

 bar recommends in these cases that a very dilute 

 solution be used. 



Inhalations of increasing amounts of pollen, 

 beginning with very minute quantities, has also 

 been tried with the idea of active immunization. 



It is probable that further study of hay fever 

 as a phenomenon of anaphylaxis will result in the 

 explanation of points concerning the disease which 

 are not yet clear. 



II. OTHER PLANT TOXINS. 



Ricin, from the seeds of Ricinus communis; 

 abrin, from Abrus precatorius ; crotin from the 

 seeds of Croton ilglium; and robin, from the leaves 

 and bark of the locust tree (Robinia pseudoacacia) 

 are chiefly of experimental interest. They are 

 similar in their action, are very toxic to animals, 

 producing both local and general changes with 

 fatal termination when given in sufficient doses; 

 they have pronounced agglutinating action on the 

 erythrocytes of most animals, and in some in- 

 stances are slightly hemolytic. By guarded im- 

 munization antitoxins may be obtained for them. 



