128 



The Ottawa Naturalist 



[Vol. XXXII. 



DIFFERENT TYPES OF GALLS: A. Linden mite gall, sometimes very ab- 

 undant on basswood leaves, note the varied forms. The interior is inhabited by 

 microscopic plant mites. B. Maple spot gall, a yellowish-red margined gall, very 

 common on soft maple; at the centre there is an almost transparent maggot. 

 C. Bud gall on the western rayless goldenrod, note the protecting brush of plant 

 hairs shown in the enlarged section. D. Goldenrod ball gall, very common, each 

 inhabited by a large stout yellowish-white maggot. E. Cypress flower gall, a 

 peculiar whitish flower-shaped growth sometimes very abundant on the twigs. 

 F. Cockscomb elm gall, a deformity produced by a plant louse and occasionally 

 very abundant on small trees, the sUt-like entrance on the under surface of the 

 leaf is shown in the upper right-hand figure. G. Downy flower gall, sometimes 

 very abundant on goldenrod. H. Witch hazel cone gall, a greenish or reddish 

 gall, sometimes very abundant and produced by a plant louse. (Author's illustra- 

 tions. Scientific Monthly.) 



