1898] SOME NEW BOOKS 423 



Two features of the book are prominent. One, for which the 

 author expresses indebtedness to the late Prof. Green, is a constant 

 appeal to actual observation and experiment, the value of which in so 

 practical a science as geology can hardly be overrated. The other, 

 which is indeed the natural corollary of the former, is the introduction 

 of numerous photographs of actual sections ami views of geological 

 interest. For this Mr Watts has peculiar facilities, as secretary to the 

 British Association Committee for collecting and preserving such 

 photographs. On the whole these photographs arc well selected, and 

 add greatly to the attractiveness of the book. But nearly all of them 

 suffer from the printing, and there are many which we have found in 

 actual use to be unintelligible to the student. Figures 13 and 19, 

 purporting to show Crinoidal and Wenlock Limestone, might be 

 almost anything, so great is the reduction. Figures 18, 60, 88, 104, 

 154, 155, 296, 297, 301, are among those that would have been more 

 effective as pen-and-ink line-drawings, such as the excellent fig. 53. 

 The introduction of cross-country sections is to be commended ; but 

 the compression of a section across the Snowdon range or the ancient 

 rocks of Pembrokeshire into three inches does not make its unravel- 

 ment either easy or pleasurable. We rejoice to see that the very clear 

 woodcuts of De la Beche are still available. As for the figures 

 borrowed from Zittel and distinguished by (Z), Mr Watts doubtless 

 knows who the true authors of most of them w T ere and has suppressed 

 the intelligence after due consideration. We allude to this because 

 there is a lamentable tendency on the part of text-book writers to 

 copy figures from other text-books, and to give credit to the copyist or 

 compiler rather than to the original author. Thus the student is led 

 in a mazy round and not to the fountain-head. 



In style and arrangement the work is remarkably clear. General 

 or doubtful statements receive their necessary qualification, so often 

 omitted in elementary text-books. Errors there may be, but they 

 are not very serious. One fault should be remedied in a future 

 edition : that is the introduction of technical terms in the legends to 

 figures, without any explanation in the text, or without cross-reference 

 to such explanation if given on a later page. Ice-tables, for instance, 

 should either have been explained, or they should not have had a 

 half-page illustration devoted to them. 



The book is a fitting celebration of Mr Watts' appointment to 

 an assistant-professorship at Mason College, Birmingham. On its 

 appearance, both the author and the beginner in geology are to be 

 congratulated. 



The Affinities of Animals 



L'anatomif. compabee des Animaux Basee sue L'embbtologie. Par Louis Roule. 

 8vo, pp. xxvi + 1972, with 1202 figures. Paris : Masson et Cie. 1898. Price 

 48 francs. 



Mr Koule is Professor at the University of Toulouse and is well 

 known by his works " Embryologie generale" and " Embryologie 

 comparee," to which the two bulky tomes before us form a natural 

 sequel. The object of the book is not to give either a systematic 

 summary of the whole animal kingdom, a detailed account of its 

 numerous variations of structure, or even an elaborate discussion of 



