9 6 



ANIMAL BIOLOGY 



each; No. 25, Notes on Mosquitoes of the U. S., loc. ; No. 42 

 Some Insects attacking the Stems of Growing Wheat, Rye, Barley, 



and Oats, 5c. ; No. 50, The 

 Cotton Bolhvorm, 25C. ; No. 51, 

 The Mexican Boll Weevil, 25c. 

 Bureau of Plant .Industry 

 FIG. 186. - Gall fly (enlarged) and oak Bulletin No. 88, Weevil-resisting 



gall with larva, and one from which Adaptations of the Cotton Plant, 



a developed insect has escaped. JOC< ^his giyes an i nstruc tive 



account of the struggle of a plant for existence against an insect 

 enemy. 



FIG. 187. Weevil on a Corylus or filbert. 



