PEPPER TREE AS A CAUSE OF HAY FEVER. 1G7 



bring on a severe attack of hay fever. In these tests (Potts, 

 1921) nine patients susceptible to the epidemic reacted strongly, 

 or very strongly, to neat pepper tree pollen, whereas five non- 

 suscejDtible persons used as controls gave no reaction. 



All these patients had been resident in Bloernfontein during 

 several epidemic seasons, the controls without having sufEered 

 from the affliction, whilst the susceptibles had suffered severely 

 every season. Each class was suitable for the purpose intended. 



(b) By inhaling the pollens. A severe attack of hay fever 

 was mduced in three patients susceptible to the epidemic by in- 

 haling the pollen through the nose. Two of these cases have 

 already been recorded (Potts, 1919). No controls, non-suscep- 

 tibles, were used. Two of these patients were tested cutaneously 

 with the neat pepper tree pollen on another occasion, when each 

 reacted strongly. 



Pepper tree pollen is, therefore, capable of causing hay fever 

 in persons susceptible to these epidemics. As this pollen occurs 

 in the air of the town during the epidemic season (and is, practi- 

 cally speaking, the only pollen which does so occur) it must be 

 inhaled by these patients, and is no doubt the cause of their 

 sufferings. Being in the air of the town pepper tree pollen must 

 also be inhaled by non-susceptible persons, but they are immune 

 to this particular poison. 



V. Pollens in the Nasal Secretion of Patients Suffering 

 FROM Hay Fever during the Epidemic. 



If virtually only one kind of pollen is occuiTing in the t'ir 

 and patients suffering; from hay-fever are shown to be sensitive 

 to it, this is probably sufficient pi-oof that this particular pollen 

 is responsible for the hay fever. But, as a further check, the 

 nasal secretion of patients suffering from the epidemic was 

 examined for poUerns. It should be explained that when pepper 

 tree pollen is mounted in nasal secretion, the majority of the 

 grains, which are oval in outline and have a conspicuous groove 

 along one side, swell to a varying degree, lose their groove, 

 become spherical and usually burst. As the wall of this pollen 

 is smooth and devoid of any markings the grains in this swelling 

 lose the characters (size, shape and groove) by which they can 

 be identified as belonging to the pepper tree. The secretions, 

 which had been discharged on to a glass sheet as soon as the 

 patient awoke, and which had solidified, w^ere first examined 

 direct but witliout shouang any pollens. Thev were then dis- 

 solved, centrifuged, concentrated to a small bulk, and re- 

 examined, when pepper tree pollen was found in all of them. 

 The number of secretions examined was four, from different 

 patients, and the number of grains of pepper ti-ee pollen un- 

 swollen, or so little swollen as still to be identifiable, found in 

 them was respectively 7, 6, 4 and 2. 



It was, perhaps, not very sui7)rising to find pepper trep 

 pollen in the nasal secretion, as pollen plates exposed in the pnrt 

 of the town where these patients slept showed pepper tree pollen 



