PLATE 54 



Crowns of alfalfa plants bearing galls caused by Urophlyctis alfalfae photographed at 

 different stages of development. 



A. — A comparatively early stage of development at which the origin of the gall 

 structures from the elements of developing buds can be traced. 



B. — A later stage of development at which the origin of the tissue has become 

 obscured. The tap root of this crown was cut off and the photograph taken from 

 below. Galls usually become considerably larger than this before they begin to 

 disintegrate if the plant continues vigorous growth. 



