130 



The Ottawa Naturalist 



[Vol. XXXIl. 



CHARACTERISTIC OAK GALLS: A. Bud-like galls on oak twigs, sometimes 

 very abundant and since they produce a sweetish fluid, hosts of bees, flies and 

 other insects may be attracted in early summer. B. Oak spangles, produced by a 

 gall midge, note the cup-like .shape and the little oval cavity at the base, shown 

 in the illustration of a sectioned gall. C. Large oak apple, one of the more 

 common and striking galls produced by gall wasps. D. Gall of the wool sower, a 

 delicate appearing white. ]iink-marked wooly growth containing seed-like cells, 

 each inhabited by a white maggot. E. Mid-rib tumor gall sectioned to show the 

 series of cells inhabited by the white maggots. F. Small oak apple, the one in 

 section shows the characteristic central cell inhabited by a maggot and supported 

 by numerous radiating fibres. G. A peculiar cylindrical-spined, rosy red, yellow- 

 banded gall on a western oak. H. Gouty oak gall, a large swelling frequently 

 forming bead-like enlargements on most of the smaller branches of various 

 oaks, large trees sometimes being badly infested. (Author's illustrations, 

 Scientific Montlily.) 



