April 7, 1898] 



NATURE 



533 



inferred from them. Roux retorts with a criticism of 

 Hertwig's control experiments on the same objects 

 (frog's ova), and it is difficult to decide between two 

 observers who mutually accuse each other of inaccuracy 

 and want of attention to detail. 



So far as one can judge the advantage in the polemic 

 lies with Roux, the more so because he invites our con- 

 fidence by asking any one who is interested to come and 

 inspect his preparations of hemiembryos, and to judge 

 for himself whether or not he has described them truly, 

 and whether they do not support the theoretical con- 

 clusions drawn from them. 



BRITISH VERTEBRATES. 



A Sketch of the Natural History ( Vertebrates) of the 

 British Isles. By F. G. Aflalo. i2mo, pp. xiv -I- 498. 

 Illustrated. (Edinburgh and London : Blackwood and 

 Sons, 1898.) 



WITH the host of books in existence on British 

 animals, it is a somewhat curious fact that, so 

 far as we are aware, there is none which treats of all the 

 vertebrates collectively, with the exception of Jenyns's 

 " Manual," published in 1835. Still more curiously, that 

 particular work happens to be omitted from the very 

 useful bibliography Mr. Aflalo gives at the end of his 

 little volume 1 Under these circumstances, the work 

 before us fills a distinct gap ; and as it is beautifully 

 illustrated and brightly written, it ought to command a 

 ready sale among those desirous of knowing something 

 about the higher animals of our islands without being 

 bored by technicalities. 



Needless to say, it is not a book for the professed 

 naturalist, and shcfuld not therefore be criticised from his 

 standpoint. It has no pretence to be an advanced edu- 

 cational text-book ; but is intended to appeal to those 

 who have the " field-fever " strongly developed, and who 

 are certainly in need of a cheap and portable volume 

 dealing with all the vertebrates to be met with by field 

 and flood in the British Isles. To be as accurate as 

 possible without being dry, to produce a chatty little 

 handbook, and not a dissecting-room manual, seems to 

 have been the main object of the author ; and in this 

 laudable endeavour, in our opinion, he may fairly claim 

 to have succeeded. 



One very notable feature in the book is that scientific 

 names are relegated to a series of tables, prefixed to the 

 groups to which they refer, and that in the text the 

 animals appear under the popular designations alone. 

 This certainly renders the volume much more readable 

 than would otherwise be the case. Special attention is 

 given to the life-history of each animal treated ; but 

 descriptive details sufficient to distinguish the species 

 from its British relatives are added, and in those cases 

 where we have perused them, appear all that can be 

 reasonably required. 



Any nomenclatural list is now-a-days open to criticism, 

 were we disposed to be critical on this subject. But in 

 the main the author appears to have steered a fairly 

 middle course between extreme innovations and old- 

 fashioned views. In one case he is clearly wrong — 

 namely, in calling the marten Martes sylvatica^ and 

 restricting Mustela to the polecats and weasels. In 



NO. 1484, VOL. 57] 



birds, we are glad to see he employs genera mostly in a 

 wide sense, so that the blackbird and ouzels appear in 

 the same genus as the song-thrush. But these are de- 

 tails in which his readers have probably little or no 

 interest, and which his critic may therefore leave alone. 



If we might suggest an improvement, it would have 

 been to curtail the amount of space devoted to the 

 sperm-whale, which scarcely comes under the designa- 

 tion of a British animal, and to give more details with 

 regard to some of the smaller mammals. For instance, 

 a little more might have been added as to the colour- 

 changes of the squirrel, and the distinctive coloration of 

 the tail of the British form ; while further information as 

 to the black variety of the water-vole being restricted to 

 damp localities might have been desirable. Perhaps, 

 however, the author is better acquainted with the tastes 

 of his readers than is his critic ; and personally we con- 

 fess to much more interest in reading the anecdotes re« 

 lating to ambergris than we should in wading through 

 details of coloration of fur and feathers — important as 

 these latter undoubtedly are in their proper place. 



As regards paper, type, illustrations (from the facile 

 pencil of Mr. Lodge), and freedom from misprints, the 

 volume appears all that can be desired. As an 

 Easter gift to friends, whether young or old, interested 

 in the natural history of our own islands — which is the 

 proper commencement of zoological studies — no volume 

 could be more appropriate. R. L. 



OUR BOOK SHELF. 



Canada^ s Metals. By Prof. Roberts- Austen, C.B., D.C.L., 

 F.R.S. Pp. 46. (London : Macmillan and Co., Ltd., 

 1898.) 

 The address which Prof. Roberts-Austen delivered at 

 the Toronto meeting of the British Association last year, 

 and afterwards repeated at the Imperial Institute, was 

 so well received on each occasion that there must be 

 many who will welcome its appearance in book form. 

 The main object of the address was to indicate the 

 nature and distribution of Canada's mineral wealth ; but, 

 to lend additional interest to the subject, and afford a 

 base for experimental illustration, a specific metal — 

 nickel — which is especially Canada's own, was given the 

 most prominent place in the discourse. 



How great is the mineral wealth of the Dominion is 

 understood by all who know the work and publications 

 of the officers of the Canadian Geological Survey. Re- 

 port upon report have been published on the mineral 

 resources of the various provinces, but they have mostly 

 gone unrecognised in England, and British efforts have 

 been tardy in developing the riches in Canadian territory. 

 Ten years ago Dr. Dawson published his exhaustive 

 and glowing report on the mineral wealth of British 

 Columbia, in which he pointed out the richness of the 

 region in auriferous deposits, and stated that alluvial 

 gold would probably be found in the bed of every tribu- 

 tary of the Yukon. Had British capitalists known how 

 to value reports of this character, they would long ago 

 have developed the Yukon basin instead of waiting 

 until the success of placer mining at Forty Mile Creek 

 in 1896 called public attention to the extraordinary rich- 

 ness of the district in precious metals. The facts brought 

 together by Prof. Roberts-Austen will, however, help to 

 make the extent and variety of Canada's mineral deposits 

 better known than they have been, and will also show 

 that, large as is the output at the present time, it will 

 certainly be enormously exceeded in the future. 



