. The Canadian field-naturalist. 40 The Canadian Field-Naturalist. [Vol. XXV. Migration and Physical Proportions, a Preliminary Study, by C. K. Averill, pp. 572-579. This is an application of mathematics to ornithological study, and is based upon series of measurements of various birds correlated with their migrational and flight habits. Birds of longest migration seem to liave long wings, short tails and small bills and feet. Tlie forked tail is an ac- companiment of good flight powers. A possible explanation of this is suggested by Dr. J. T. Nichols in a later number of the National Geograph
. The Canadian field-naturalist. 40 The Canadian Field-Naturalist. [Vol. XXV. Migration and Physical Proportions, a Preliminary Study, by C. K. Averill, pp. 572-579. This is an application of mathematics to ornithological study, and is based upon series of measurements of various birds correlated with their migrational and flight habits. Birds of longest migration seem to liave long wings, short tails and small bills and feet. Tlie forked tail is an ac- companiment of good flight powers. A possible explanation of this is suggested by Dr. J. T. Nichols in a later number of the National Geographic Magazine, where he calls attention to the forked tails of the speedier fish. His theory is that the center of the tail is the meeting point of the stream line currents proceeding along the body and that the cutting out of the tail here reduces drag. It also appears in current literature that a remarkably speedy motor boat has lately been built by cutting away the underbody aft in an analogous fashion. It would seem that the effect produced in water currents would probably be seen in air movement with a result pro- portional to the reduced density of the medium. The forked tail may have a greater meaning than has heretofore been imagined. Mr. Averill has suggested a promising line of investigation. Under "General Notes" are the follow- ing: The Willet in Nova Scotia, pp. 581-582. Breeding of the Semipalmated Plover in Yarmouth Co., , pp. 583-584. The Black-polled Warbler and Bick- nell's Thrush'in Yarmouth Co., pp 591-592. Notes on the Acadian Sharp-tailed Spar- roAv, pp. 587-589. The Singing of the Ruby-crowned King- let, pp. 594-596. Notes from Seal Island, , pp. 596- 597. All by Harrison F. Lewis. The Willet in Nova Scotia, by Chas. W. Townsend, pp. 582-583. Most of these are summarised by their titles. The Eastern Willet as a breeding bird seems to be increasing in Nova Scotia under the beneficial pr(5iecSanj<jf the Mi- gratory Birds Convention Ac
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