56o 



NATURE 



[April 12, 1900 



the book before us is nothing if not scientific and modern 

 in its treatment of the subject. It attempts in the first 

 place to do justice to the claims of every one of the 

 principal existing groups of animals, fairly and without 

 favour or prejudice, giving an outline of the structure and 

 morphology of the more important types in each class. 

 In the second place, it introduces the reader to the funda- 

 mental conceptions and problems of zoology, such as 

 evolution, classification and phylogeny, distribution in 

 space and time, conjugation, fertilisation, development, 

 and the cell theory. In a work of scope so wide and 

 comprehensive, with at the same time such narrow limits 

 of space, it requires much care and ingenuity to steer a 

 just course between the Scylla of over-condensation and 

 perplexity and the Charybdis of vague incompleteness. 

 The inexperienced reader becomes bewildered, in the 

 first case with excess, and in the second with lack of 

 detail, so that he is at a loss how to sort out, or how to 

 connect, the material which he absorbs. The danger is, 

 therefore, that a treatise of this kind may be used less by 

 the beginner, who requires to be stimulated and interested, 

 than by the more advanced student, who desires merely 

 to "look up" work he has done ; in other words, that it 

 • may degenerate into a mere cram-book. It must be 

 admitted, however, that if it is possible to succeed in such 

 a task, the authors have done so. The book contains a 

 great store of information, chosen with judgment and 

 set forth with skill. In order to avoid as much as possible 

 the dangers above pointed out, the authors have restricted 

 the extent of ground covered by leaving out some of the 

 less important groups, such as Chimaeroids among fishes, 

 by omitting all descriptions of extinct groups, and by 

 dealing only very briefly with embryology. Perhaps the 

 chief value of the work is in its numerous and admirable 

 illustrations, of which the authors had a copious stock to 

 draw upon in the pages of their larger two-volume " Text- 

 Book." Amongst them are some coloured diagrams 

 of the circulation of the blood in various types, for the 

 most part clear enough, but Fig. 204, illustrating the 

 circulation of a fish, certainly requires a good deal of 

 looking at before its meaning can be grasped. The book 

 is intended, we are told, principally for the requirements 

 of the students in higher classes of schools ; but is it 

 necessary, even in this educational stratum, to explain 

 the meaning of commensalism by coining and printing 

 such a word as " messmateism," which looks at first like 

 some new form of theosophy ? These are, however, but 

 minor points. Judged as a whole, the book is one which 

 fills a distinct gap in zoological literature, and fills it well, 

 as a handy book of reference, though we are inclined to 

 think that the authors have attempted rather too much, 

 and that the class of readers who will benefit most by 

 their work will not be quite those for whose use the book 

 was intended. 



The second book mentioned at the head of this 

 notice will be welcomed by many as a handy and 

 inexpensive manual of zoology adapted to the needs 

 of elementary, and especially medical, students, which is 

 at the same time free from the faults and vices of the 

 harmful, unnecessary cram-book. It is written on the 

 same plan as the well-known " Elementary Biology " of 

 Huxley and Martin ; that is to say, a certain number of 

 types are selected, and a connected account of each one | 

 NO. 1589, VOL. 61] 



is given first, after which follow practical directions, 

 necessarily rather brief, for its study and dissection. The 

 examples selected are Amoeba and some other unicell^jlar 

 organisms, illustrative of the differences between animals 

 and plants ; Hydra and Bougainvillea ; the earthworm, 

 crayfish and pond-mussel ; and the amphioxus, dogfish, 

 frog and rabbit. The frog is taken first and dealt with 

 in detail, occupying nearly half the book, as an intro- 

 duction to biology in its various branches — anatomy, 

 physiology, histology, embryology, classification and 

 various biological problems. Then follow the descriptions 

 of the other types, beginning with the unicellular forms 

 and ending with the vertebrates ; and a final chapter 

 deals with the cell and with fertilisation and embryology. 

 The illustrations are numerous and useful, some of them 

 from familiair cliches, others appearing for the first time. 

 The book, it may be safely predicted, will become 

 popular and will run through further editions, in which, 

 doubtless, alterations will be made to keep it up to the 

 level of advances in science. In the present issue, the 

 most recent standpoint of vertebrate embryology is 

 not quite adequately represented. Thus more might 

 have been made of the frequent occurrence of what 

 may be termed the amphioxus stage in the embryonic 

 development of many systems of organs in Craniata, as 

 for instance the appearance, in the development of the 

 vascular system, of a splanchnopleuric subintestinal 

 vein, prior to the formation of the somatopleuric system 

 represented by the cardinal veins, &c., and the origin of 

 the heart itself from the anterior portion of the former 

 system. Again, in the urogenital system the differences 

 between pronephric and mesonephric tubules, both in 

 development and structure, and the homology of the 

 former with the excretory tubules of amphioxus, might 

 at least have been alluded to. The authors do not raise 

 the question as to whether pronephric and mesonephric 

 tubules are to be regarded as homodynamous or not, but 

 leave one rather with the impression that they are ; it is 

 surely time now, however, that the English, no less than 

 the German, student (and, for that matter, the English 

 teacher and examiner also) should be told clearly that they 

 are not. The concluding chapter of the book might, in 

 fact, have its interest, as well as its value, increased in 

 many particulars, without adding half a page to its length. 

 But this detracts little from the usefulness of the book as 

 a guide and help to the student and teacher of zoology, 

 and as such it may be confidently recommended. 



E. A. M. 



THE TEACHING OF METEOROLOGY. 

 Practical Exercises in Elementary Meteorology. By 

 Robert DeCourcy Ward, Instructor in Climatology in 

 Harvard University. Pp. viii -I- 195. (Boston, U.S.A. : 

 Ginn and Co., 1899.) 



MR. ROBERT D. WARD has written a book for 

 the use of schools and training colleges, which we 

 should think would be very popular with teachers and 

 pupils alike. With the former, because he indicates to 

 them the proper method of giving instruction in meteor- 

 ology, and, at the same time, supplies so many valuable 

 hints, that he makes their work more profitable, without 



