190 



DISEASES OF CULTIVATED PLANTS 



the form of miniature pins with pale yellowish heads, and 

 1-2 mm. high. 



During January 1908 a large consignment of diseased 

 berries was received at Kew from Costa Rica. The berries 



FIG. 50. Sphaerostilbe flavida. i, leaf showing disease ; 2, 

 section showing conidia form ; 3, surface view of white spot bear- 

 ing conidial stage of fungus ; 4, section showing perithecia ; 

 5, two perithecia ; 6, ascus containing eight spores. Fig. i 

 reduced ; remainder mag. 



had been carefully packed, and arrived in a good condition 

 for experimenting with. These were placed in Petri dishes 

 on sterilised damp blotting-paper. At the expiration of 

 seven weeks dense groups of minute, bright-red perithecia 



