A FAUNA OF THE MORAY BASIN.
[TO THE EDITOR OF THE "SPECTATOR."]
SIR,—I have read with much interest an article on the above subject in the Spectator of August 29th, but it seems to me the writer uses an unfortunate, or rather let me say a mis- leading, expression in one place. If I am wrong you must pardon the ignorance of one of the aborigines in the back- woods of Canada. The writer says that the birds follow in their migrations the river valleys and the lowest depressions in the watersheds "because they follow the lines of least resistance." To use a slang phrase, this seems like a large order ; where does the resistance come from ? In swimming, which is analogous to flying, the greater the depth the greater the support, and therefore the easier it is to swim. Do not the birds fly over the depresbions in the watersheds where they find a greater depth of air, and therefore greater support You may call this if you like least resistance, but is it not better to call it more support ? If I am wrong you must pardon my stupidity.—I am, Sir, &a., [We do not think the expression is misleading. The resistance referred to is that of the mountains, which opposs the birds' progress, not that of the air.—En. Spectator.
Previous page
