18 
Tilia americana. Townsend, C. H. T. 1886. Coleoptera found in dead 
trunks of Tilia americana L. in October. Can. Int. 18:65-68. 
TYPHACEAE 
Typha. Claassen, P. We. 1921. ha insects: their ecological relation- 
ships. N. Y. (Cornell) Ag. Expt. Sta. Mem. 47:457-531. 
ULMACEAE 
Ulmus. Hoffman, C. He 1940. Additions to annotated list of insects 
reared from elm bark and wood. Brooklyn Ent. Soc. Bul. 
Ulmus. Hoffmann, C. He. 1942. Annotated list of elm insects in the U. 
Se Ue Be Dept. Ag. Misc. Pub. 466320 PPpe 
Ulmus americana. Pechuman, L. L. 1937. An annotated list of insects 
found in the bark and wood of Ulmus americana L. in New York 
state. Brooklyn Int. Soc. Bul. 32(1):8-21. 
VIOLACEAE 
Viola. Chittenden, F. He 1901. Some insects injurious to the violet, 
rose, and other ornamental plants. U. S. Bur. Ent. Bul 27: 
114 pp. (See ROSACEAE) 
VITACEAE 
Vitis. Gentner, L. G 1925. Some important grape insects. Mich. Ag. 
Expt. Sta. Spec. Bul. 148:19 pp. 
SECTION II. THE PRINCIPAL WORKS OF CHARLES ROBERTSON 
1886. Notes on the mode of pollination of Asclepias. Bot. Gaze 9(10):262-269. 
1887. Insect relations of certain Asclepiads. I, II, Bot. Gaz. 12(9):207-216; 
1889, Flowers and Insects. I-III. Bot. Gaze 14(5):120-126; 14(7):172-178; 
14(12) 297-304. 
1890. Flowers and Insects. IV, V. Bot. Gaz. 15(4):79-84; 15(8) :199-204. 
1890. Flowers and Insects-Umbelliferae. Acad. Sci. St. Louis Trans. 5:449-460 
1891. Flowers and Insects. VI. Bot. Gaz. 16:65-71. 
1891. Flowers and Insects, Asclepiadaceae to Scrophulariaceae. Acad. Sci. St. 
Louis Trans. 5:569-598. 
1892. Flowers and Insects. VII-IX. Bot. Gaze 17(3):65-71; 17:173+179; 
17 (9) :269-276. 
