PLATE 50 



Urophlyctis alfalfae: 



Section of diseased bud scale of alfalfa, showing four coalescing cavities, in three of 

 which the large primary turbinate cells taa, tba, and tc may be distinguished; taa has 

 not started to proliferate any resting spore, while the resting spore produced by tba is 

 moderately young, although turbinate cells of later orders tab, tbc, and others have 

 produced resting spores further along in development. The thickening of the host cell 

 walls bounding the cavity and the enlargement of the host nuclei hn lying free within 

 the cavity are conspicuous. Note also the large dimensions of the nucleus in the 

 uninucleated turbinate cell tbbx and the relatively larger proportions of the nucleoles 

 in the nuclei of the resting spore rs. Drawn with the aid of the camera lucida. X 860. 



