142 NATURAL SCIENCE. August. 



When the work is complete it is sincerely to be hoped that it will be 

 bound up together and placed on the open market. 



F. A. B. 

 Another Text-Book of Zoology. 

 Lehrbuch der Zoologie fur Studirende und Lehrer. By Dr. J. E. V. Boas. 



Lector der Zoologie an der Kgl. Landw. Hochscule Kopenhagen. Pp. 503, 



427 illustrations. Second and enlarged edition. Jena : Gustaf Fischer, 1894. 



Price 10 marks. 

 In the increasing multitude of foreign and English text-books, itis not 

 always easy to see any but local pretext for the issue of the books. 

 It is natural and right that where a teacher is honoured in the 

 country in which he teaches, his students should have his written as 

 well as his spoken word. This text-book is written specially for 

 medical students, students of veterinary science, and so forth. Those 

 of us who have taught or examined similar students in England will 

 wonder with a great admiration at the range and thoroughness of 

 the course of zoology mapped out for these in Copenhagen. In a 

 general part of eighty-eight pages Dr. Boas gives an account of the 

 animal body on the old Hunterian plan of division into tissues and 

 systems. Then he treats rapidly but briefly the special problem of 

 Morphology, the plans on which animal organisms are built, the 

 embryological growth of organisms, and the relations of the diverging 

 types of adult structure to each other. Next he treats of various 

 biological problems, such as the influence of sessile life, the duration 

 of life, adaptations, the relations of animals to their environment, and 

 so forth. All this is as simply and as philosophically done as we have 

 seen in any book, and Dr. Boas's students are to be congratulated on 

 their teacher. The systematic part is equally well written. In inver- 

 tebrates the most typical or the best known species only are referred 

 to. In vertebrates the enumeration of species is carried out much 

 more fully. 



The illustrations are all good. There are many old friends and 

 many desirable additions. Altogether we have nothing but praise 

 for this text-book. While it is not conspicuously better than the other 

 leading books of the same kind, it is thoroughly satisfactory for its 

 purpose, and much better than any English text- book or translation. 



A Geological Text-book. 

 Geology. A Manual for Students in Advanced Classes and for General Readers. 

 By Charles Bird, B. A. Lond., F.G.S. 8vo. Pp.429. London: Longmans, 1894. 

 Price 4s. 6d. 



The illustrations constitute the feature in which this book differs 

 most markedly from most works of the kind. These fall into three 

 groups. First, and most important, a new set processed from 

 photographs, some from those by Messrs. Wilson, chiefly of coast 

 scenery, mountains, rivers, and old volcanic tracts, which are 

 admirable in selection and in method of reproduction ; the rest, of 

 rocks, minerals, and fossils in the Jermyn Street Museum, often of 

 figured or type-specimens, among which special attention should be 

 given to figs. 145, 214, 23i,and237; both of these sets of illustrations 

 are excellent and will give more than a passing value to the pages 

 they adorn. Secondly, there are illustrations, for the most part good 

 ones, borrowed from earlier works, some with adequate acknowledg- 

 ment, as in the case of those from the works of Green and Bauerman, 

 others without, like figs. 170, 211, 239,259, 261, 287, which appeared 

 first in Woodward's " Geology of England and Wales." Thirdly, 

 those which have been recovered from some forgotten talus heap, or 



