Smithsonian Report. 1936. — Smith 



Plate 2 



J. p. Doncaster. 



VIOLAS Showing a color Variegation Considered to be Caused by a Virus. 



Note the penciling and flecking of the petals. 



Ann. AppL Biol. 

 SECTION OF A POTATO LEAF WITH THE BEAK OF A SUCKING INSECT IN SITU. 



Insects which feed in this manner are most concerned with \-irus transmission. 



