Hagen ] 74 [January 3. 



Letter from Mr. H. S. Treherne. 



Poughkeepsie, N. 1\, Dec. £6, 1876. 

 Dr. H. A. Hagen. 



Sir: — Happening to look over the number of the "American 

 Naturalist " for July, 1876,1 noticed your paper on the "Probable 

 Danger from White Ants," and I concluded to trouble you with a 

 letter. The system of surveying and marking out lands in Manitoba 

 and the Northwest Territories is similar, I believe, to that used in the 

 Western States, namely — the land is laid out in blocks of a mile 

 square. At each half mile a trench is dug and a mound raised, and 

 in the centre of the mound a wooden post is planted, having about 

 two feet in the ground and about two and a half feet above. As 

 timber is very scarce, except small " bluffs " of poplar trees, upon the 

 prairies these posts are generally made of poplar. Poplar wood is 

 well known to be very soft and to dry very quickly. 



Nearly every post that had been planted over a year, which I 

 came to while upon some engineering work out there, I found to be 

 what I at first considered very loosely sunk into the ground, but 

 upon examination I found them eaten through and through by ants. 

 At first I imagined that the nest was in the post, since so many tun- 

 nels and passages had been bored through it, but I never managed to 

 find what I searched for, until I despaired of ever finding the 

 " queen." 



One day we set our teamsters to move camp, and pointed out upon 

 a rough map the exact spot we wished the field commisariat officer 

 to pitch the new camp. We did not arrive in camp until nearly 

 dark, and too tired to look around us. The next morning, however, 

 I noticed within two or three yards of my tent a small hillock, which 

 was evidently an entrance to an ant's nest, since it was formed of 

 small, dry, sandy knobs of earth, through which a very great number 

 of small sticks, about an inch long and one-sixteenth of an inch in 

 diameter, were scattered. For about three feet down these knobs 

 and sticks were found, the nest seemed then to tend in a southerly 

 direction. About a hundred feet away in the same direction as the 

 nest tended was one of the posts and mounds mentioned previously. 

 This mound was swarming with ants, and the post was riddled with 

 their galleries, so I concluded that it was a part of the same nest. 



The workers were whitish with yellow heads, and appeared to be 

 blind. The winged ants were of a rich brown, with head blackish 

 brown and brownish antennas, wmgs very frail and white, and the 



