234 



RESEARCHES ON FUNGI 



containing the apothecia was taken into a corridor of the laboratory 

 and placed in the position shown in Fig. 113. A box lined with 

 black paper was used to provide a black back-ground. The table 

 was so arranged that direct sunlight illuminated the apothecia 

 without shining into the box. A small object was then placed on the 



Fig. 1 14. — A photograph showing spore-clouds which have been emit- 

 ted by the puffing of numerous apothecia of Sclerotinia sclerotiorum 

 ( = S. libertiana) grown from sclerotia. It was taken in bright 

 sunlight with an exposure of about one-hundredth of a second 

 about one second after tlie dish (shown in Fig. 113) covering the 

 fruit-bodies liad been raised. The simultaneous discharge of the 

 contents of millions of asci doubtless produced air currents which 

 were a factor in raising the spore-clouds above the apothecia. 

 Photographed by L. F. Dickson and W. R. Fisher at Cornell 

 University. About two-fifths the natural size. 



top of the middle of the dish and focussed with the camera. When 

 everything was prepared, the photographer stood ready at the 

 bulb of the camera and, at a given word, the dish was quickly 

 removed from the apothecia. Nothing happened for about one 

 second, and then the apothecia suddenly discharged clouds of spores 

 into the air. At the right instant an exposure of a very rapid 

 photographic plate was made for one-hundredth of a second, with 

 the result shown in Fig. 1 14. 



