222 



PLANT DISEASES 



can be prevented by immersing the seed for five minutes in 

 hot water at 127 F. 



Fig. 53. Urocystis occulta. i, upper part of a rye 

 plant diseased; 2, spores, one of which- has germinated 

 and produced a cluster of secondary spores at the apex of 

 the germ-tube, X3oo; 3, a spore that has germinated 

 and produced secondary spores, two of which have 

 germinated, a, x 300. 



Prillieux, Mai ad. des Plantes Agric., vol. i. p. 187, figs. 



