Alfalfa in Kansas. 



351 



a pea to the size of a man's fist, being irregular in contour. The surface 

 of these galls is irregular, coral-like, due to the undulations. Very many 

 fine, thread-like root hairs are seen growing from these galls. If such a 

 gall is cut in two, many cavities filled with a dusty mass of brown spores 

 will be observed. 



FIG. 299. Crown wart of alfalfa. 

 The wart is seen at the crown of the 

 plant, [After E. C. Fields, U. S. 

 Department of Agriculture.] 



FIG. 298. Stem cracking disease of al- 

 falfa. Notice the depth to which these 

 cracks extend. 



The disease is serious in Europe, and recently it has beer found in 

 the western part of the United States. Although it is said to be re- 

 stricted in Europe to fields which are wet, seldom appearing in drier 

 land, such does not appear to be the case in this country, for it has been 

 reported on both well-drained and poorly drained land, and on "sticky" 

 soils. How and whence the disease was introduced into the Salt Lake 

 valley, Utah, is not known. In all probability the spores or germs of 



