Leeches 51 



ing be made six feet instead of four. This will have the effect of 

 draining off the warm ground waters more completely and at the 

 same time make it more difficult for leeches wintering on the borders 

 of the area to escape." 



Owing to the mildness of the winter of 1920-21 and especially 

 to the paucity of the snowfall Major Welch declined to draw off 

 the water, fearing that the spring run-off might prove insufficient 

 to reestablish the old level. 



During 1921-22 conditions proved much more favorable for a 

 repetition of the experiment and under date of May 29, 1922, 

 Major Welch wrote: "When the first freeze [of the preceding 

 winter] came the lake was full and we immediately drew it down. 

 Within two or three days the water had lowered about four feet and 

 just after this we had a period of very severe weather which froze 

 the ground very' thoroughly before the snow came. Of course, it 

 is too early in the season to say what the result has been and as soon 

 as we have an opportunity to observe, I will be very glad to give 

 you all the facts." 



On September 14, 1922, Major Welch wrote further: " I am very 

 glad to be able to inform you that the leeches have not been in 

 evidence at Lake Stahahe this year. I am not sure that they have 

 all been destroyed although I have been unable to find any nor can 

 I get any reports from the camp directors on this lake which lead 

 me to believe that they have found any. If we have a good oppor- 

 tunity this winter to again lower Lake Stahahe and freeze the mud 

 over its shallow areas we shall do so in an endeavor to entirely 

 eliminate these leeches." 



This statement of Major Welch is confirmed by Miss R. M. 

 Joliffe, Mr, E. F. Brown's successor as Superintendent of the Camp 

 Department who writes (Nov, 3, 1922) : " We had no trouble so 

 far as I know with leeches in Lake Stahahe last summer;" and by 

 the direct testimony of camp directors, twelve out of fifteen of whom 

 replied to a questionaire. 



Two directors report leeches more numerous in 1922 than in 192 1, 

 one adding that they had decreased in number from 1919 to 1921, 

 four that they were less numerous and five much less numerous in 

 1922, while one fails to answer this question. Answering the ques- 

 tion how many campers were known to have been bitten during the 

 season, six reply none, three one, one two, and two eight or ten. It 

 is rather interesting that both of those directors who reported leeches 

 as more numerous in 1922 also state that none of their campers were 

 bitten during the season and one adds that very few were seen all 

 summer. Most of the directors state that few or even no leeches 

 were seen and the two highest estimates of the number seen are 

 about five daily and twenty-five for all summer. 



These camps are located all around the lake and more than half of 

 them are very near to census stations at which the leech population 

 was counted in 1919 and 1920. The two camps where an increase 

 was reported are both located at the south end of the lake. One 

 of the most significant statements is that of Mr. Wm. Demerest, of 



