Vol. xxi"! 

 1904 J 



Recent Literature. S^^ 



spring route, which crosses North America ahnost centrally from the 

 coast of Texas to the Arctic Barren Grounds. 



Most important of the ' new facts ' are the statistics given under ' migra- 

 tion and temperature,' and under ' variations in the speed of migration' 

 over different portions of the continent, in accordance with the change in 

 the direction of the isotherms. The explanation given of the increase in 

 the distance of dailj travel after passing the northern boundary of the 

 United States of such birds as visit Alaska and that portion of the 

 Dominion of Canada west of the Makenzie Valley, is eminently reason- 

 able and satisfactory. The subject is clearly illustrated by means of a 

 map showing the ' Speed of the Robin in Migration,' which indicates not 

 only the acceleration of the progress of the Robin as it advances north- 

 ward, but also the position of the isotherm of 35" at monthly periods from 

 January 15 to June 15. 



Finally, ' The Unknown ' ! Among the chief mysteries that await solu- 

 tion are the winter haunts of the Chimney Swifts, which disappear from 

 our ken the moment they leave the northern coast of the Gulf of Mexico 

 in the fall until they reappear there the last week in March; another 

 equally deep mystery is the winter whereabouts of the Bank Swallow. 

 The route of the Cliff Swallow from Brazil to California, and how the 

 Red-eyed Vireo reaches southern British Columbia at the same time it 

 reaches Nebraska, and before they have appeared in any of the interven- 

 ing countr}', are among the problems, says Mr. Cooke, " that continually 

 vex and fascinate the investigator." It is certainly encouraging to see the 

 " mj'stery of mysteries" of the old Gatkean and allied points of view 

 dwindling to such small proportions in the eyes of modern investigators 

 who trust to facts rather than to figments of the imagination in their 

 attempts to elucidate the problems of migration. — J. A. A. 



G. M. Allen's 'The Birds of New Hampshire.' 1 — In this excellent 

 paper of 200 pages, an attempt has been made, sajs the author, "to bring 

 together a list of the species of birds known to have occurred within the 

 State of New Hampshire during historic times, together with a general 

 account of their distribution, faunal position, times of migration, and, in 

 the case of the rarer species, a detailed list of the known instances of 

 ■ occurrence." While published records have been utilized, " a consider- 

 able body of unpublished facts relative to the birds of the State is here 

 included," partly based on the author's own observations and partly on 

 those of other ornithologists who have made generous contributions from 

 their notes, and for which due acknowledgments are made. " The 

 sequence of names and their spelling," the author states, '' are strictly 



1 The Birds of New Hampshire. By Glover Morrill Allen. Proc. Man- 

 chester Institute of Arts and Sciences, Vol. IV, Pt. I, 1902 (1903), pp. 23- 

 222. Published about June 15, 1904. 



