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, x 300 ; 3, a spore that has germinated 

 and produced secondary spores, two of which have 

 germinated, u, x 300. 



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



