144 DISEASES OF THE SWEET PEA 



lation is carried out. The s3Tiiptoms pro- 

 duced in artificially inoculated plants are 

 similar to those in the field. 



STREAK DISEASE 



Bacillus lathyri Manns and Taub. 



Streak is the only bacterial disease 

 which affects this plant and no disease 

 of the sweet pea is so little known to 

 the growers. The attention of Professor 

 Manns and the author was called to it 

 in the course of our investigations, that 

 is to say, only about three years ago. 

 It probably has existed, however, a long 

 time in this country, since it attacks so 

 many other members of the legume family, 

 the red clovers particularly, upon which 

 it causes trouble of considerable economic 

 importance. In England this disease is 

 ruining the sweet pea crop every year. In 

 this country it has gained a strong foothold 



