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., N.S., pp. 583-584. 



The Black-polled Warbler and Bick- 

 nell's Thrush 'in Yarmouth Co., N.S 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, N.S., 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 Act. It was only 

 lately supposed to be nearly extinct but 

 may after all come back again. For some 

 time all Willets on the Atlantic coast were 

 referred to the western form, but now it is 

 on the cards for observers there to sharpen 

 their eyesight once more and differentiate 

 between them. All birds now can not be 

 automatically referred to the Western as 

 the only geographic possibility. Had not 

 observers been but too willing to rely on 

 geographical preconceptions in identifying 

 we miglit have known some time ago that 

 the Eastern Willet Avas still to be reckon- 

 ed with. 



Under "Recent Literature" the follow- 

 ing papers are mentioned or reviewed. 



The Eyes of the Burrowing Owl, with 

 Special Reference to the Fundus Oculi, by 

 Dr. Casey Wood, Reprinted from Coniii- 

 hutions to Medical and Biological Research, 

 dedicated to Sir William Osier in Honor 

 of his Seventieth Birthday by his pupils 

 and Co-Workers, pp. 819-823. 



A new Jay from Alberta, by James Lee 

 Peters, Proc. New England Zool. Club, 

 VII, pp. 51-55. 



This is a new subspecies of Canada Jay, 

 Perisorens canadensis albescens, described 

 from Red Deer, Alta. from specimens in 

 the Brewster collection now in the Museum 

 of Comparative Zoology, Cambridge, Mass. 

 It is declared to be paler than other known 

 races. 



Report of the Canadian Arctic Expedi- 

 tion, 1913-1918, Vol. IX, Part E., Acan- 

 throcephala. 



In this is described a new species of 

 acanthrocephala, Filicollis a.cticus, para- 

 sitic on the King Eider in the western 

 Canadian Actic. It is interesting to note 

 that the King Eider does not carry the 

 same infestation throughout its range. On 

 opposite sides of the Arctic Circle it seems 

 to be parasitized by acanthrocephala re- 

 presenting two distinct genera. 



Notes on the Harlequin Duck (on Bri- 

 tish Columbian Coast), by Chas. E. Alford, 

 British Birds, XIV, June, 1920. 



The Trumpeter Swan in British Colum- 

 bia, by Allan Brooks, London Field, July 

 31, 1920. 



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