222 PLANT DISEASES 



can be prevented by immersing the seed for five minutes in 

 hot water at 127° F. 



tN 



c? 



0> 



/ 1 



im/y/ 





^' 







2 





h \i 



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, a, X300. 



Prillieux, Malad. des Flantes Agric.^ vol. i. p. 187, figs. 



