90 RESEARCHES ON FUNGI 



the fruit-body at intervals in much the same manner as steam is 

 swept by air-currents from the surface of hot water. 



In the month of July, 1905, I was fortunately enabled to make 

 direct observations upon the falling of the spores from the fruit- 

 bodies of Polyporus squamosus. My attention was first called to 

 this matter by Mr. C. Lowe, the laboratory attendant. A log, 

 producing fruit-bodies of the fungus, had been placed in the 

 experimental greenhouse at the Birmingham Botanical Gardens. 

 Going into the greenhouse one morning, it appeared to Mr. Lowe 

 that some one had been smoking there. On looking round he 

 observed that the " smoke " was coming from the underside of 

 a freshly-grown fruit-body which was some 10 inches in diameter. 

 From that morning onward until the thirteenth day, every time 

 the greenhouse was entered (morning, afternoon, and as late as 

 nine o'clock in the evening), the clouds of spores were observed 

 coming off from the fungus. On the thirteenth day the clouds 

 were very feeble at nine o'clock in the morning and ceased to be 

 visible about an hour later. Black paper was then placed under 

 the fruit-body and on this the white spores collected. By changing 

 the paper at intervals, I was able to satisfy myself that the spores 

 continued to fall in fairly large quantities for three days more. The 

 black paper was whitened by the spores, but only very feebly on 

 the last day. Altogether, therefore, these observations proved that 

 the spores had been falling continuously for sixteen days. 



The clouds of spores, which were watched by the hour against 

 a black background, resembled the steam coming off a cup of tea 

 or the finest tobacco smoke. The wreaths and curls of spores 

 appeared to originate in eddies made by air-currents in passing 

 over the hymenial surface. Tapping the fruit-body so as to make 

 it tremble did not appreciably increase or diminish the clouds 

 of spores. The wreaths could be made by artificial air-currents 

 produced by movements of the hand near the fruit-body. Some 

 of the wreaths could still be seen after they had floated away to 

 a distance of two yards. The clouds were distinctly visible on a 

 black background when they were observed at a distance of ten 

 yards from the fruit-body. 



The log upon which the fruit-body was growing Avas watered 



