NATURE 



581 



THURSDAY, APRIL 24, 1902. 



PRACTICAL ZOOLOGY FOR BEGINNERS. 

 Leitfaden fiir das zoologische Praktikum. Von Dr. 

 Willy Kiikenthal. Zweite, umgearbeitete Auflage. 

 Pp. viii + 304; 169 illustrations. (Jena: Fischer, 

 1901.) Price 7 mk. 



THE character of a work on practical zoology for 

 beginners will differ fundamentally according to 

 the particular point of view of the author. If the attain- 

 ment of a thorough grasp of the organisation of a few 

 animals be held to be the best means of developing 

 the capabilities of a beginner, we are naturally led to 

 the type-system of which Huxley was the pioneer, and 

 his " Practical Biology," used conjointly with Prof. 

 Howes' biological atlas, will remain a classic. 



The German school, on the contrary, has developed 

 another system ; it gives the beginner at once a general 

 outline of the animal kingdom, and concurrently a large 

 number of animals are superficially e.xamined. 



There are arguments that can be advanced for 

 either system. The broad outline of the animal kingdom 

 provided by the German laboratories tends to arouse the 

 interest of the student, and it is undoubtedly worth while 

 to sacrifice much to accomplish this end ; for without 

 intelligent interest very little need be expected from the 

 pupil. On the other hand, it must be admitted that such 

 a system of instruction can too readily degenerate, and 

 the result on the student's mind is likely to be but a con- 

 fused assemblage of ill-digested facts. It may well be 

 doubted whether a cursory glance over the whole animal 

 kingdom constitutes as valuable a training for the future 

 investigator as a thorough study of a few well-selected 

 types. 



In our universities we have to satisfy the needs of 

 three classes of students : — (i) those seeking a general 

 scientific education, (2) the future investigator and 

 specialist in zoology, (3) the future medical man. The 

 endeavour to deal with all three classes of students in 

 the same manner cannot be wholly satisfactory ; but a 

 student beginning the study of zoology will probably not 

 at first have the intention of becoming an investigator, 

 and it would in practice be very difficult, or impossible, 

 to separate the first two classes of students. Accordingly 

 we must be content with arranging separate courses for 

 the general student and the medical student. 



The work by Dr. Kiikenthal is primarily intended as a 

 practical aid in the laboratory for the generalstudent begin- 

 ning his subject. The opinion as to how far the author has 

 succeeded in his diflScult task will greatly depend on the 

 particular bias of the individual teacher. That the book 

 has had a certain measure of success in Germany is 

 evinced by the fact that the first edition appeared only 

 three years ago. 



The book begins with a rather meagre account of the 

 apparatus required and of the general manipulation of the 

 microscope. The body of the work consists of twenty 

 chapters, each of which is divided into three parts : — 

 (i) practical instruction in manipulation and the material 

 required, (2) an outline sketch on the subject of the 

 chapter, (3) a special description of one or more types. 

 NO. 1695, '^O^- ^5] 



The first chapter deals with the elements of histology. 

 In the outline sketch, the nature of a cell and the general 

 characters of tissues are shortly described. In the 

 special description an amceba, white blood-corpuscle of 

 the frog, egg of mussel and examples of the various 

 tissues are very briefly introduced. The fact that a 

 nucleus is capable of dividing is only just mentioned, 

 although surely even a beginner ought to be shown 

 preparations illustrating karyokinesis. 



Each of the remaining chapters deals with one group 

 or several allied groups of animals, and at the beginning of 

 every phylum there is given a descriptive classification. 

 The chapter on the Protozoa begins with an excellent 

 account of events taking place in a hay-infusion, then in a 

 single page the general characters of the group are sum- 

 marised, while in the special description of types we find 

 representatives of most of the more important classes of 

 Protozoa ; but the Foraminifera and Sporozoa are 

 omitted. The Hydrozoa arealsodealt with satisfactorily; 

 the special descriptions include the following instructive 

 series : — Hydra, Tubularia, Cordylophora, Clava, Tiara, 

 Obelia, Liriope, Aurelia and Nausithoii. 



The difiiculty of such comparative treatment increases 

 greatly as we pass to the more complicated Metazoa, 

 and the author's accounts of the various groups tend to 

 be decidedly unequal. Thus there is a brief description 

 of the groups Bryozoa and Chstognatha, and among the 

 Mollusca the genera Chiton and Sepia are included ; yet 

 of the Crustacea there is only Daphnia and a rather in- 

 adequate account of the crayfish. Also, in a book of this 

 character the student might surely be somewhat further 

 introduced to such larval forms as Trochosphere, Nauplius 

 and Pluteus than by the mere mention of their names. 



The chapters on the Vertebrata are the least satis- 

 factory of the book. In some seventy pages we find 

 Amphioxus, perch, frog, lizard, pigeon and rabbit. It 

 may be doubted whether such an abridged account could 

 be of much use to the beginner, and the descriptions 

 take more after the method of a text-book than of a 

 practical guide for the student in the laboratory. In- 

 serted here and there are a few directions as to dissection, 

 but without the constant aid of a demonstrator it is 

 certain that an ordinary student could make but little of 

 them. There are practically no figures of the vertebrate 

 skeleton, blood-systems or nerves. 



With the exception of the vertebrate section, the book 

 is well illustrated with good figures, which appear in 

 most cases to have been selected with much care. The 

 appearance of one incorrect figure may be noticed. The 

 series of diagrams after Boas (Fig. 30) showing the sup- 

 posed stages in the degeneration of the medusa into a 

 sporosac do not correspond to facts. The sporosac 

 represents the degeneration of the whole of the medusa, 

 and is not simply the persistent manubrium. There 

 are a considerable number of original sketches 

 which bear the impress of being drawn directly from 

 dissected specimen, and are consequently especially 

 useful to the student. The original drawings of the star- 

 fish and sea-urchin deserve particular mention. 



In the opinion of the reviewer, we are in need of a 

 compromise between the English and German methods 

 of dealing with the beginner, in fact, a work intermediate 

 in character between Huxley's " Practical Biology" and 



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