184 



PEPPKR TltKE AS A CAUSP: OF HAY FEVER. 



in IMoemfontein and Kiinberley for the same length of time. On 

 five of the fourteen j^lates, one kind of pollen was present, and, 

 though its identity could not be determined, it was not that of 

 the pepper tree. Its presence indicated that, during part of the 

 period of. exposure the weather, which on three of the days of 

 exposure was reported as very hot and windy, had been suitable 

 for the dispersal of at least that kind of pollen. From reports 

 received from four doctors, it appeared that there was no hay 

 fever about at the time and that hay fever is never prevalent 

 there, though one doctor reported having, in his own mind, 

 " traced two cases of acute conjunctivitis to pepper trees." No 

 pepper tree pollen was found on any of the plates. Weather 

 reports for the month are given in Table XVI. The mean maxi- 

 mum temperature and mean difference between the wet and dry 

 bulb during the eight days of exposure were 77-3°F. and T-l^F. 

 respectively. 



