212 NATURE-STUDY REVIEW [12:5— May, 1916 



organs (Malpighian tubules) of the larva is the primary cause of the 

 development of this gall. Secretions from other parts of the body 

 may also have an influence. 



In conclusion, it may be said, that gall insects and insect galls 

 furnish a fascinating field for study, especially since there is still 

 so much of interest and of importance that is not known about 

 them. 



Literature List 



The following titles have been selected from the hundreds of 

 papers that have been published on this subject. 



i. Adler, H. and Straton, C. R. 1894. Alternating Generations, A 

 Biological Study of Oak Galls and Gall Flies. 



2 Beutenmiiller, W. 1904. The Insect Galls of the Vicinity of New 

 York City. American Museum Journal, vol. 4. 



3. Cannon, W. A. 1900. The Gall of the Monterey Pine. American 

 Naturalist, vol. 34. 



4. Connold, E. T. 1902. British Vegetable Galls. 



5. Cook, M. T. 1902-1904 Galls and Insects Producing Them. 

 Ohio Naturalist, vol. 2, 1902; vol. 3, 1903; vol. 4, 1904. 



6. Cook, M. T. 1 902-1 904. Preliminary List of Gall-Producing In- 

 sects Common to Indiana. Proceedings of the Indiana Academy of Science, 

 1 902- 1 904. 



7. Cook, M. T. 1910. The Insect Galls of Michigan Michigan 

 Geological and Biological Survey. Publication 1. Biological Series 1. 



8. Felt, ,E. P. 1096. Insects Affecting Park and Woodland Trees. 

 New York State Museum, Memoir 8. Vol. II. 



9. Heindel, R. L. 1905. Ecology of the Willow-Cone Gall. American 

 Naturalist, vol. 39. 



10. Kiister, E. 191 1. Die Gallen der Pflanzen. 



11. Packard, A. S. 1890. Insects Injurious to Forest and Shade Trees. 

 Fifth Report of the U. S Entomological Commission. 



12. Thompson, M. T. 191 5. An Illustrated Catalogue of American 

 Insect Galls. 



13. Triggerson, C. J. 1914. A Study of Dryophanta Erinacei and its 

 Gall. Annals of the Entomological Society of America, vol. 7. 



