338 PEPPER TREE POLLEN AND HAY FEVER. 



In considering the conclusions to be drawn from the reactions 

 of the patients to the tests, the case of patient No. 15 will be 

 omitted, as although described as a non-sufferer, this patient 

 turned out on subsequent enquiry to have been resident in Bloem- 

 fontein only one month. He had previously lived in Johannes- 

 burg where, it is true, he had not suffered from hay fever, but 

 the epidemic under investigation does not occur there; and, as 

 he had not resided in Bloemfontein during the epidemic season 

 his susceptibility had not been put to the test. In view of the 

 fact that he reacted strongly to the pepper tree pollen his condition 

 during the next epidemic season, if he is still in Bloemfontein, 

 will be watched with interest ; but, for the reasons already given, 

 he is an unsuitable patient for this particular experiment. 



All the patients recorded as susceptible have been resident in 

 Bloemfontein several years and suffer severely every season from 

 the disorder. With most of them I have been in regular commu- 

 nication during the last two seasons, and the group includes some 

 of the worst sufferers in Bloemfontein; indeed, the majority 

 might perhaps be more correctly described as highly susceptible. 

 The patients recorded as not susceptible, the controls, had also 

 been resident in Bloemfontein diiring several epidemic seasons 

 and without having suffered. All the patients, therefore, with 

 the exception of No. 15, were eminently suitable for the purpose 

 of the experiments. 



The scarifications were made on the outer side of the upper 

 arm, four on each patient, about one and a half inches apart, 

 and the materials tested were laid on the skin and gently mixed 

 with the exuding serum ; in the case of the solutions as much liquid 

 was used as would conveniently stay on the scarified region without 

 running off. 



Neat Pollen. 



Very great difficulty was experienced in obtaining the pollen 

 in sufficient quantity. The weather at the time was dull and 

 moist, and when a flowering male shoot was shaken the open male 

 flowers fell off, but very little pollen fell out of the anthers. Even 

 when the flowers were dried, crushed, and passed through a fine 

 sieve, examination proved that it was the half empty anthers that 

 were obtained, most of the pollen having stuck to the sieve and 

 other utensils with which it had been brought into contact. 

 Attempts to pick the pollen out of the anthers were also unsuccess- 

 ful, partly again because of the stickiness of the pollen, but mainly, 

 in this case, on account of the minute size of the anthers. Finally, 

 a method was devised by which the very stickiness of the pollen, 

 the character which had caused most of the difficulty, was used to 

 separate it from the flower. The open fresh flowers were shaken 

 from a male shoot and were then rolled or rubbed between two 

 circular sheets of plate gflass of a size such as to be easily held in 

 the open hand. The pollen stuck to the glass and was then easily 

 removed with a razor and transferred to a bottle. The material 

 obtained in this way was found to be almost pure pollen, with 



