REVIEWS 337 



First Lessons in Practical Biology. By E. W. Shann, B.Sc, F.Z.S. [Pp. xv 

 + 256, with 71 figures.] (London : G. Bell & Sons,; 1922. Price 5s. net.) 



This book excellently fulfils its author's purpose, which is to introduce to 

 the upper middle school a serious and scientific study of biology. 



As presented by Mr. Shann, the study of plants, animals, insects, and fishes 

 and their interrelations, together with the conditions governing their increase 

 and development, proves most interesting, and while essentially practical the 

 book is neither too elementary on the one hand nor too technical on the other. 



Practically all the objects chosen for examination, dissection, and experi- 

 ment are common and abundant in any rural district, while the few exceptions 

 can easily be purchased from the usual sources. 



Teachers in schools with a rural bias or where biology figures in the 

 curriculum will find this book eminently suitable for seasonal work. The 

 elementary treatment of variation, mutation, heredity, and Mendelism is 

 especially noteworthy. E. H. 



Practical Zoology for Medical and Junior Students. By J. D. F. Gilchrist, 

 M.A., D.Sc, Ph.D., and C. von Bonde, M.A. [Pp. xi + 344, with 

 105 illustrations.] (Edinburgh : E. & S. Livingstone, 1922. Price 

 15s. net.) 



Since the publication of Huxley and Martin's Pyadical Biology and 

 Marshall and Hurst's Practical Zoology little advance has been made on 

 those beautifully planned and carefully thought out books. 



Since their appearance, however, syllabuses have changed and facilities 

 for teaching greatly improved ; there would therefore seem to be a genuine 

 need for a revised laboratory guide for junior students in Zoology. 



A defect of some of our modern books appears to us to be in the artificial 

 separation of gross anatomy from microscopical structure, the latter being 

 frequently omitted altogether except in the case of those organisms, such as 

 Protozoa or the Earthworm, for which the microscope is indispensable. 



If the teaching of Zoology is to be truly morphological and not merely 

 the gross anatomy of a series of types, the analysis of structure must be 

 carried deeper and the microscopical characteristics studied side by side 

 with those revealed by dissection. 



No comparison of the vertebrate types, for example, is complete without 

 a study of the structures of the skin in each, nor can the evolution of the 

 internal, middle, and external ears be properly understood without a study of 

 sections, however elementary. Finally, to take a third example, the coelome 

 and the relations of the organs thereto can be grasped in no way so easily 

 as in a transverse section through the trunk of, say, a dog-fish embryo. 



The interpretation of serial sections, a problem which the student must 

 sooner or later encounter, can be usefuUy introduced at this stage, too, by 

 the study of thick slices of the adult dog-fish. 



With these ideas in mind, it is with some disappointment that we read 

 Prof. Gilchrist's book. We find little attention given to microscopical 

 features of the higher types. The directions for dissection are not very 

 copious in proportion to the descriptive matter. The new diagrams have 

 few new features. We believe that diagrams in practical textbooks should 

 be limited to illustrating the directions for dissection. Complete diagrams 

 are too inclined to discourage the student from observing for himself and 

 recording things as he finds them. 



The book is well printed and bound — perhaps too elegantly for the rough 

 usage of the laboratory. The blank pages for sketches will appeal to many, 

 although they are made of the same rather thin smooth paper as is used 

 for the letterpress. 



The book will recommend itself to students in the Cape by the inclusion 

 among the types described of two commonly found in South Africa. 



J. H. W. 



