420 Bihliographical Notices. 



have a series of trustworthy notes from whatever countries are in- 

 habited or traversed by the migratory tribes. We feel sure of this 

 that migration is far more vniiversal among birds than is generally 

 supposed. Mr. A. E. Knox has already done good service by caUing 

 attention to this, as well as by his own excellent observations. It is 

 to be hoped that no English Ornithologist will think his time and 

 pains ill bestowed upon a subject so promising and so inexhaustible. 

 Too little is known of the direction taken by the various migrants ; 

 often in spring, they appear to follow quite a different route to 

 that of the autumn. How are they affected by prevailing winds ? — 

 by clear or foggy weather ? How long are they on their way ? At 

 how many stages do they linger ? — and are they much or little delayed 

 by changes of temperature, when they have once set out ? All these 

 are most interesting points ; and we trust some light may eventually 

 be thrown upon these questions as the number of observers becomes 

 every year increased. 



Mr. Tristram, worthily following the example set by Mr. Wolley, 

 has been the discoverer of the native haunts and nests of several birds 

 whose eggs were previously little or not at all known. 



The study of eggs is one essential to the Ornithologist. It is too 

 true that instances are not wanting of collectors who are content to 

 possess the eggs as so many pretty objects, hardly knowing anything 

 of the birds themselves ; and no little mischief has been done in this 

 way by the stimulus given to the extirpation of rare species. But 

 the scientific student is compelled to commence his investigations " ab 

 ovo," and thus he is led to detect the really native haunts of his 

 birds. There are, in the present volume, two excellent chapters 

 bearing upon the study of eggs, — one by the veteran Hewitson, the 

 other a review of two recent works upon American and German 

 Oology. As usual with the German Avriters, we find Herr Badeker 

 too much inclined to found new species upon slight differences, and 

 fortifying himself in this by the inverted system of reasoning from egg 

 to bird, instead of from bird to egg (p. 404). It occurs to us that 

 the terms "European" and "British" are somewhat too loosely ap- 

 plied to eggs when they belong to birds which, it is true, must be 

 included in the respctive Faunas of Europe and Britain, but whose 

 eggs there is no reason to expect we shall ever find upon European 

 or British soil. In what sense the egg of the American White-winged 

 Crossbill can be called "British," it has always puzzled us to discover, 

 though it is very likely the Americans may have some day to thank 

 an Ibis-worshipper for leading him to its " cunabula." 



When we read that the Knot and Sanderling, so well known upon 

 our shores, have hitherto battled the utmost pursuit of their nests, 

 when we hear that at the North-east Cape, in latitude 78° N., these 

 birds were still pressing onwards, we are almost compelled to ask with 

 the writer may there not be some circumpolar land (or islands) un- 

 visited as yet, except by these adventurous Sand-pipers ? At the 

 same time, we think too nuich stress should not be laid upon the 

 negative evidence of one observer, posted upon an isolated point of 

 that vast region, whether his station was unfavourable from its 



