9b 



THE REPORT OF THE 



No. 19 



larvse found in the cells are white and plump, and waxen in appearance, 

 and have sharp mandibles. They are liable to attacks from predaceous 

 secondary parasites. (Fig. 16). 



B, b. There is a two-winged fly (Trypeta solidaginis, Fitch), which 

 forms a large, round, pithy gall in the stems of the Golden Rod (SoUdago 

 Canadensis, L.). The larva has its cell in the centre of the gall, but bites 



Fig. 16. a. Gall on Blueberry. Natural size, 

 showing cells of Guest-fly. Natural size, c 

 Greatly enlarged. 



h. Section of Gall , 

 Larva of Guest-fly . 



a passage to the outer rind. Through, this passage, probably, an insidious 

 foe finds its way, viz., Eurytoma gigantea, Walsh. I gave a minute des- 

 cription of this species, both of the male and of the female, in the Canadian 

 Entonvologist, vol. xxvi., p. 122. 



The country naturalist, who takes the trouble to study the plant galls 

 and their inhabitants, finds many things to awaken his interest and to ex- 

 cite his admiration. 



AN ELEMENTAEY STUDY OF INSECTS. 



By Prof. W. Lochhead, Guelph. 



The late Prof. C. Y. Piley, of Washington, estimated the number of 

 kinds of insects on the earth at ten millions. Of this immense number only 

 200,000 are known, yet these make up two-thirds of all the kinds of animals 

 known. The question will naturally arise : In what way do insects differ 

 from other animals? Although they differ much among themselves, all in- 



