PLATE io 
A. —A blighted Viroflay spinach plant from Ohio. (Original.) 
B. —Interior of cage 4, in which the aphids and blighted spinach plants were allowed 
to remain. Note the stunted growth and yellowed cotyledons erf the seedlings as 
compared with those in cage 2 (Pl. 11, A), grown under insect-free conditions. 
(Original.) 
