Parasites, Diseases and Enemies. 279 



something of this plant in the report of the United 

 States Fish Commission for 1884-5, but did not know 

 it. Late in July, 1889, I was ordered by Mr. E. G. 

 Blackford, President of the New York Fish Commis- 

 sion, to make an examination of the two principal lakes 

 of Long Island, at Ronkonkoma and Riverhead, and 

 Dr. Bashford, Dean of Columbia University, volun- 

 teered to assist, I to work up fishes and crustaceans, 

 and he to do the same for plants and insects. A full 

 report of our work may be found in the report of the 

 State Commission for 1889. 



When Dr. Dean showed me the plant it was well 

 known by sight, but the idea of those little bladders, 

 one-sixteenth of an inch long, destroying a fish seemed 

 absurd. Dr. Dean did' not have to go far to study the 

 plant. Three varieties the Utricularia vulgaris, Pinior 

 and Pur pur ea were found in the Long Island ponds 

 in quantity and under natural conditions. The plant 

 is found in rope-like masses growing from a big round 

 bud. It is more or less floating, and dies at one end 

 as it grows at the other. In the winter the stem dies 

 up to the terminal bud. It blooms in June in Long 

 Island waters, its yellow clusters of flowers reaching 

 up above the surface of the water. The leaves are deli- 

 cate and fringe the stem. From their axils arise the 

 bladders. From its small size I am skeptical about its 

 taking any fish. 



INSECTS AND THEIR LARV^). 



While furnishing food for trout, as well as other 

 fishes, there are some species of insects which turn the 

 tables and kill the trout. A flat beetle (Belostoma gran- 

 dis) grows to a length of two inches, and will attack a 



