1909J The Ottawa Naturalist. 151 



small "jogs" and turns in them, and they cannot be said to be 

 the shortest distance between two points, but their general 

 direction is straight enough from the nests to the aphis colonies. 

 They are quite smooth and free from blades of grass or other 

 obstructions, but they are not very easy to trace as the long grass 

 conceals them, and occasionally they disappear entirely in a 

 tunnel a few inches long. In fine weather traffic on them is \ery 

 active, and numerous parties of workers are continually running 

 to and fro. 



Before I regretfully tore one up in tracing it to the nest, 

 thirteen feet of the longer road mentioned above was entirely 

 subterranean, being tunnelled at a depth of about an inch under 

 the sod . My brutal devastation of their work at first caused 

 great excitement among the ants, but before I had left the ravag- 

 ed scene, the workers had begun repairs in the most philosophic 

 manner, and w^hen I revisited the spot a week or two later, the 

 road was all clear and smooth' again. Indeed, their determination 

 to "keep the line clear" seems to be as strong as it is in the most 

 zealous railway superintendent. When traffic is brisk, a pinch 

 of earth placed across the road as a barrier creates a great com- 

 motion. There is a tumultuous running back and forth and a 

 climbing over the barrier and around it. But presently a single 

 worker, who has recovered her equinamity sooner than the rest, 

 is seen dislodging particles of the encumbering earth with her 

 jaws and depositing them in the grass at the edge of the road. 

 After a little she is joined by others, and in a comparatively short 

 space of time the obstruction is removed and the road is clear 

 again. Any cricket or grasshopper that blunders on to the 

 highway is promptly attacked and quietly driven off by the 

 menacing jaws of the ants. 



THE NITROGEN COMPOUNDS IN RAIN AND SNOW. 



Our readers inay remember that we presented in the issue 

 for October 1908, an account of the interesting work carried on 

 by the Chemical Division of the Dominion Experimental Farms 

 in the determination of the fertilizing value of rain and snow. 

 It was there stated that from the analysis of each fall of rain 

 and snow it had been calculated that during the year ending 

 February, 1908, 4.323 lbs. of nitrogen had been furnished to 

 the soil per acre, and of this approximately 75 per cent, had been 

 present in rain and 25 per cent, in the snow. 



