" V , i 3 X ] Becent Literature. 73 



day, during their journey north or south." A little attention to the report 

 on 'Mississippi Valley Bird Migration,' by Professor Cooke (which, by 

 the way, there is nothing in the book to show that our author ever heard 

 of) would have shown that we are not left to the "wildest guesses" on this 

 subject, or that anything like an average journey of "300 miles per day" 

 is ordinarily made by birds while on migration. The Dotterel (Eudro- 

 mias morinellus), which "breeds on the tundras of Arctic Euro-Asia, and 

 winters in Africa, north of the Equator," he supposes to make the "enor- 

 mous flight of quite 2000 miles" between these two points, "without a 

 rest, and between sunset and sunrise," — or, to put the case more definitely, 

 by flying at the rate of 200 miles an hour from 7 p.m. of one day till 5 a.m. 

 of the next — an average rate of three and one-third miles per minute for 

 ten consecutive hours! "Each migratory bird," he says, "must have a 

 wonderful knowledge of the topography of its own particular routes, aided 

 by its marvellous power of memory and keenness of sight. I would 

 suggest, however, that the migration flight reaches its highest altitude 

 when passing over seas. These offer no landmarks, no bearings, nothing 

 that ma a serve as a guide; consequently the line of flight rises to a suffi- 

 cient altitude to enable the bird to bridge the passage with its keen powers 

 of vision." Besides: "The mere mechanical labour of flight is rendered 

 much easier of performance in the more rarefied atmosphere of these 

 lofty regions of space." 



Although the author so modestly characterizes his book "as only a 

 pioneer" in this interesting field, where previously was merely a "chaos" 

 of "raw and tangled data," the reading of the two chapters entitled 'The 

 Philosophy of Migration,' and 'Routes of Migration,' to say nothing of 

 the one on 'Glacial Epochs and Warm Polar Climates,' begets the feeling 

 that if all Mr. Dixon says is to be taken as sound "Philosophy" and 

 knowledge "reduced to Law, " little is left for future investigators to settle 

 among all the many hitherto troublesome problems relating to the migra- 

 tion of birds. However extensive Mr. Dixon's researches may have been 

 into the literature of the subject, he rarely gives his readers any clue to 

 the sources of his information, or any opportunity for verification of 

 alleged facts. There is, in fact, hardly a direct citation of any work or 

 paper on the subject, excepting a few references to some of the author's 

 former works, and a few references given in the chapter in which the 

 subject of hibernation is treated. Many of his assumptions and theories, 

 however, are not new. 



For the most part the author's treatment of the subject is more or less 

 oracular. His agreeable style and considerable power of imagination, 

 aided by a fair conception of the general subject, despite a rather loose 

 grasp of the underlying facts, will doubtless render his book an attractive 

 one to the general reader, and a profitable venture for both author and 

 publisher. The book, though at|many points untrustworthy, is suggestive, 

 and it may be read with interest and profit by even those who may not 

 approve of all of the author's generalizations. — J. A. A. 



