34 Roosevelt JJ'ild Lite Bulletin 



ing was above. This trap proved a total failure. Xot a single leech 

 was caught by it. 



The third form of trap was a little pen four feet across, con- 

 structed of four boards driven into the bottom and the banks and 

 fastened by stakes, the whole having the outhne shown in figure 17. 

 This was constructed at a shallow point on the south shore where a 

 saw mill had been operated, and where some old boards were lying 

 about to afford shelter for leeches. The bank here is about a foot 

 high, abrupt, and composed of a rich black earth covered with a good 

 growth of grass. The depth of water within the pen varied from ten 

 inches at the outer to four inches at the shore end. Several flat stones 

 and pieces of board were placed within to afford concealment for 

 any leeches that might enter. The trap was baited with blood as 

 were the others, and although used for only one week in the latter 

 part of August proved rather more successful than the other traps. 

 Three visits yielded seven leeches, though it is not certain that some 

 of these may not have been overlooked when the bottom and banks 

 were thoroughly searched for leeches before the trap was baited. 



From these experiments the impracticability of trapping, at least 

 by any of the methods adopted, was thought to be sufficiently estab- 

 lished. Certainly these traps proved far less effective than human 

 traps in the shape of boys at the swimming docks. 



Even had the traps proven several times as effective the expense 

 would have condemned their use. \"arious experiments and observa- 

 tions would indicate that tmder ordinary- conditions which, of course, 

 var\- greatly, the average range of attractiveness of a leech bait does 

 not exceed an extreme limit of fifty feet in any direction. This would 

 give to each trap a maximum effective range of about 100 feet of 

 shore. The shore line of this lake is approximately four miles or 

 21,180 feet long. Consequently a complete line of traps around the 

 entire lake would require not less than two hundred. The expense 

 of tending the traps would also be hea\y. IXIr. Fletcher and I work- 

 ing together found that about twenty minutes were required to raise, 

 examine, clean, rebait and set one of the experimental box traps. 

 With an effort directed toward speed, and with improvements in the 

 manner of weighting and for facilitating the escape of air so that 

 they would sink more rapidly this time could be cut in two, making 

 six traps per hour or forty-eight per day of eight hours for two men. 

 The entire time of four to eight men would therefore be required for 

 this work. 



There being no local slaughter-house some difficulty was had in 

 arranging for a regular supply of blood. This was finally 

 secured from Xew York abattoirs through two avenues, Air. 

 Daschner of the Bear ^Mountain Inn and the Tuxedo !Meat and 

 Provision Company, to both of whom my thanks are due. The 

 blood was shipped on ice in glass jars or tin cans and always reached 

 me in good condition. From the first it was noticed that it remained 

 fluid, was of a remarkably bright red color and would seldom putrefy 

 until the third da}-, even during the warm weather of midsummer. 

 For this reason it was suspected that it might have been treated with 



