PLATE 82 
Pemphigus populi-transversus: 
A. —Gall on poplar cutting. Cuttings were collected before the buds began to 
swell and were planted in sand in flowerpots kept in a greenhouse at Baton Rouge, 
La. Young stem mothers of Pemphigus populi-transversus , obtained indirectly from 
winged female migrants from roots of crucifers, were placed on growing cuttings on 
March 23, 1916. The photograph, taken on May 27, shows pot containing cuttings. 
One developing gall can be seen on twig at upper left. 
B. —Gall shown in A, enlarged to nearly natural size. Beside it can be seen the 
slit of a small gall which has failed to develop to any considerable extent. 
