def 
1914] Life History of Hydromyza Confluens. 147 
(and possibly the self-pollination) of N. americana and may be 
summed up as follows: (1) The coincidence of the blooming 
period of N. americana with the maximum appearance of the 
adults of Hydromyza confluens; (2) The large numbers of 
flies limited in distribution to the immediate vicinity of the 
lily beds; (8) The assembling of the flies in large numbers 
within the flowers when the latter have opened sufficiently 
to admit them; (4) The heavy loads of pollen which are carried 
by many of the flies and the almost universal presence of 
varying quantities of pollen on all individuals; (5) The continu- 
ous blooming of N. americana throughout the greater part of_ 
August, so that at any given time there were flowers in all degrees 
of maturity, a fact which eliminates a difficulty due to the pos- 
sibility that a given flower is -proterogenous; and (6) The 
behavior of the adults in preferring to pass from place to place 
by crawling and by very short flights (usually the former when 
possible) rather than by extended flights, which means a 
maxium of contact of the insect with the various parts of the 
supporting plant. 
LITERATURE CITED. 
Bembower, W., 1911. Pollination Notes from the Cedar Point Region. The 
Ohio Naturalist, 11:378-383. 
Elliot, G. T. S., 1896. Flower-haunting Diptera. Trans. Ent. Soc. London, 
pp. 117-118. (Abstract in Am. Nat. 30:760, taken from Journ. Royal 
Micr. Soc.) 
Fulton, B. B., 1911. The Stratiomyide of Cedar Point, Sandusky. The Ohio 
Naturalist, 11:299-301. 
Johnson, C. W., 1904. A Supplementary List of the Diptera of New Jersey. Ent. 
News, 15:157-163. 
Lovell, J. H., 1898. Three Fluvial Flowers and their Visitors. Asa Gray Bulletin, 
6:60-65. 
1902. The Colors of Northern Polypetalous Flowers. Am. Nat., 
36:203-242. 
Miller, G. S. and Standley, P. C., 1912. The North American Species of Nymphea. 
eee from the U. S. National Herbarium, 16:63-108, 12 pls., 
40 figs. 
Needham, J. G., 1908. Notes on the Aquatic Insects of Walnut Lake. Appendix 
Ill. A Biological Survey of Walnut Lake, Michigan, by T. L. Hankinson. 
A Report of the Biological Survey of the State of Michigan, Published 
by the State Board of Geological Survey as a part of the Report for 
1907, pp. 252-271. 
Robertson, C., 1889. Flowers and Insects. I. Bot. Gaz., 14:120-126. 
Department of Entomology, Kansas State Agricultural College, Feb. 26, 1914. 
