June 22, 1893] 



NATURE 



17: 



practical disinfection, based mainly on the report of the 

 Committee on Disinfectants of the American Public 

 Health Association. 



The third part, the most important division of the 

 book, deals with pathogenic bacteria in detail, and is 

 prefaced by a description of their modes of action, and 

 of the ways in which they may gain access to the system. 

 Here too we find a discussion on the difficult subjects of 

 susceptibility and immunity, to which indeed Dr. Stern- 

 berg has elsewhere made important contributions. The 

 discussion is lengthy and impartial, and well deserves 

 careful reading. Relying on recent experimental 

 evidence, the author reaches a guarded conclusion that 

 acquired immunity depends on the formation of 

 antitoxins in the bodies of immune animals. Subsidiary 

 weight is given to the view, which he formerly upheld, 

 that the cells of the body may acquire tolerance to the 

 toxic products of pathogenic organisms, and also to the 

 doctrine of phagocytosis, to which he gives a partial assent. 

 A recent lecture by Metschnikofif on the latter subject is 

 reproduced in extenso. It is impossible here to follow 

 in detail the descriptions of the different pathogenic 

 bacteria. The order in which they are discussed is 

 necessarily somewhat arbitrary, but is convenient, and 

 follows the broad grouping into micrococci, bacilli and 

 spirilla. Amongst the pyogenic organisms Fehleisen's 

 Streptococcus erysipelatos is frankly placed as identical 

 with Streptococcus pyogenes, an arrangement with which 

 many will not agree. Altogether no less than 158 

 organisms are described as pathogenic for man or the 

 lower animals, and according to their relative importance 

 the descriptions are in large or small print— an arrange- 

 ment convenient for the student. A section follows on 

 bacteria in diseases not clearly proved to be of bacterial 

 origin, and the whole concludes with a classification of 

 pathogenic organisms from a pathological standpoint. 



The fourth part of the book deals with saprophytic 

 bacteria, special chapters being devoted to bacteria in 

 air, in water, in soil, in or on the human body, and in food. 

 The total number of saprophytes described is 331. The 

 merit of a work of this kind depends less on the number 

 of species described than on the clearness and accuracy 

 of the descriptions, and Dr.' Sternberg has spared no 

 pains to make these as complete as possible. To 

 facilitate the recognition of species a chapter on bacterio- 

 logical diagnosis has been added, in which the different 

 organisms are grouped according to their form, cultural 

 characters, and other peculiarities. This section will be 

 an important aid to the student in identification. A 

 lengthy and well-classified bibliography brings the work 

 to a conclusion, and the whole is well indexed. The 

 author is to be congratulated on the success with which 

 he has accomplished a difficult and laborious task. 



TEXT-BOOKS OF ZOOLOGY. 

 Lekrbuch der Zoologie. By Prof. Richard Hertwig, of 



Munich. (Jena : Gustav Fischer, 1891.) 

 Zoology of the Invertebrata. By Arthur O. Shipley, 



Fellow of Christ's College, Cambridge. (London : A. 



and C. Black, 1893.) 



IT is a difficult matter to say much that is readable 

 about text-books which are produced by teachers 

 with a view to the limited requirements of their own 

 NO. 1234, VOL. 48] 



jjupils. Some text-books are, so to speak, obviously ad- 

 dressed to the world — are intended by their authors to be 

 consulted both by the advanced student who is himselt 

 a teacher, and by all serious followers of the science 

 dealt with. Others have their justification in being 

 epitomes of a professor's or lecturer's teaching, suitable 

 to his immediate pupils. The former class challenge 

 criticism, and have a high standard of interest ; the latter 

 class are hardly fit subjects for appreciation, and possess 

 a very limited importance. 



Prof Hertwig's text-book of Zoology is one which will 

 no doubt be found serviceable by his pupils, and by the 

 younger students of German universities. It is con- 

 structed on the usual lines, and contains nothing either 

 in treatment or illustration which the author would 

 probably wish to submit to his colleagues as novel or 

 important. It has not the stamp of originality and fresh- 

 ness which gives a character and significance to Prof. 

 Berthold Hatschek's unfinished text-book. It is well 

 illustrated by the aid of the new " process " methods, 

 and must be estimated as much by the judgment dis- 

 played in the omissions necessary in so condensed a 

 work as by the actual statements which it embodies. 

 The latter are, though not novel, sufficiently up to date. 



Mr. Shipley's book on the -Invertebrata appeals to an 

 even more limited circle than Prof. Hertwig's. Pro- 

 fessedly it is addressed to those who only wish to learn a 

 very little about zoology, and who will be content to dis- 

 pense with all bibliography, and even with reference to 

 the names of authorities for the statements and for the 

 systems of classification which Mr. Shipley incorporates 

 as accepted fact. Presumably Mr. Shipley's book is in- 

 tended for Cambridge students who take zoology in Part 

 I. of the Tripos, and do not proceed to Part II. The 

 book will no doubt prove useful to these students. To 

 others, a more critical, more comprehensive, and more 

 authoritative treatment of the subject must be recom- 

 mended. To those who are not acquainted with special 

 circumstances which may have determined the author's 

 procedure, it must appear a matter for regret that when 

 producing a volume so well printed and largely illustrated 

 he did not make it more thorough. It is not possible to 

 discuss the opinions adopted by Mr. Shipley upon several 

 questions of interest, because he himself does not treat 

 them argumentatively, but rather as matters of information, 

 to be accepted by the pupil from his tutor. Zoology, 

 when deprived both of history and of argument, is 

 singularly uninteresting, and will perhaps in this shape 

 gain approval as a subject of school-education. 



E. Ray Lankester. 



OUR BOOK SHELF. 

 Das Gcnetische System der chemischen Elemente. Von 



W. Preyer. (Berlin: R. Friedlander und bohn, 1893.) 

 The treatment of the material contained in this book is 

 based on the idea that the elements have been produced 

 from hydrogen, or ether, or primordial matter, by a pro- 

 cess of condensation. 



The fourteen horizontal rows of the periodic table are 

 regarded as representing fourteen different degrees of 

 condensation of the initial substance, and the rows are 

 then connected together so that they fall into five different 

 groups, each of which group constitutes a generation. 



