124 DISEASES OF THE SWEET PEA 



a beaded appearance; or else the swellings 

 are very large (fig. 19) so as to be mistaken 

 for bacterial nodules, which occur nor- 

 mally in great abundance. Root galls, 

 however, cannot be mistaken for legume 

 nodules, since the latter in the case of the 

 sweet pea are lobed and are attached at one 

 end (fig. 18) ; whereas, the root galls pro- 

 duce a swelling of the entire surface of the 

 part affected. Infected plants usually 

 linger for a long time, but they can be dis- 

 tinguished by a thin growth and yellow 

 sickly looking leaves and stems. 



Distribution. The eel worm of the 

 root knot, as it is more often called, seems 

 to be of wide distribution, being found 

 in Europe, Asia, Africa, Australia, and 

 both North and South America. Al- 

 though it is found in most parts of the 

 world, there are many localities in which 

 the pest has never been known. 



