106 REPORT OF THE COMMISSIONERS OF 



When the May-fly is in season the trout and other fish simply gorge on them, and 

 they occur all over the Northern United States and the Dominion of Canada. They 

 are called the Day-fly because their winged life is supposed to be limited to a single 

 day, but this is not so. When I conceived the idea, as I did a few years ago, of trans- 

 planting the Green Drake to waters where they were unknown to serve as fish food, I 

 caught a large number of the flies as they came from the water and confined them in 

 biscuit tins perforated to admit air, and in the wire portion of a bait bucket. They 

 lived for nearly two days under my observation, when I was suddenly called away, and 

 I know not how much longer they did live. There may be some species that do not 

 live longer than one day, but it is of record that the species shown in Fig. 3 have been 

 known to live a week. I might say, if any one cares to know it, that the figured 

 specimen is Hexagcnia bilineata of Say, and is from an example taken by Prof. Lintner 

 near Schenectady in the month of June. 



The flight of the May-fly at its height has been compared to a snowstorm, and I 

 have seen them covering the entire front of a large summer hotel, windows, doors and 

 every inch of woodwork, as though the house had been plastered with May-flies for a 

 purpose. This was because at the height of their flight the wind had blown them 

 against the house. I have also seen the empty larvae cases of the May-fly thrown up 

 on the shore of a lake by the waves in a regular windrow. So it is not a difficult 

 matter to obtain the flies for transplanting. That they have been transplanted success- 

 fully I discovered soon after I experimented with the flies to find how long they would 

 live. An English officer, Major G. W. Turle, transplanted the flies and the larvae and 

 established them in new waters. Swammerdam's " Life of an Ephemera " is only 

 partly correct in describing the propagation of the May-fly, and yet it is quoted as 

 authentic : 



" When the female has emerged from the water and cast off her skin she passes 

 the contents of the double ovary into the water, but first she moves to and fro on the 

 surface of the water as if in sport, and flits about with a rapid, exploring motion. Imme- 

 diately after the eggs are passed into the water they are fertilized by the male" (this 

 is incorrect, as the eggs are fertilized before they are deposited in the water), " which 

 has previously emerged and cast off a delicate membranous skin. The eggs sink 

 slowly and are scattered over the mud at the bottom of the stream." It is unnecessary 

 to quote further from Swammerdam, for his description of the life of the larvae of the 

 May-fly is too technical for a paper of this character, and in some particulars further 

 investigation has shown that he was wrong, although in the main correct. It requires 

 two years for the larvae of the May-fly to pass from the egg to the winged stage of its 

 existence, and at all stages it furnishes first-class food for fishes. When the flight of 

 the flies takes place the larvae rises to the surface of the water, bursts its case, unfolds 



