56 NATURAL SCIENCE [January 



A System of Bacteria 



System der Bakterien : Handbuch der Morphologie, Eiitwickelungsgeschichte und 

 Systematik der Bakterien. By Dr W. Mignla. Band I., Allgemeiner Teil. 

 8vo, pp. viii + 368, with 6 plates. Jena: Gustav Fischer, 1897. Price, 12 marks. 



Of the makino' of books on bacteriology there is' no end, yet as very 

 many of these books are scarcely worth the paper they are written 

 on, any really solid contribution to bacteriological literature ought to' 

 meet with due appreciation. Dr Migula's first volume gives ample 

 promise of a very useful work, and contains a general survey of the 

 classification, morphology, and development of schizomycetes. It is 

 much more than a text-book ; it is full, not only of well-digested in- 

 formation, but of original facts and suggestive hypotheses. The first 

 section is devoted to a historical review of the classification, which con- 

 cludes with the author's own scheme, a later modification of that already 

 published by him in Engler and Prantl's work. The second and most 

 interesting section deals with morphology and life-history, and the 

 chapters treating of controversial questions, such as spore-formatiouy 

 pleomorphism, etc., are worth reading, not so much for their weight 

 as evidence as for their suggestiveness. Argument is perhaps hardly 

 Dr Migula's strong point, and we think he is too apt to put forward 

 as facts statements which, while unsupported as they often are by the 

 quotation of a single instance, we are bound to regard as assumptions. 

 These very statements, however, often contain ideas well worth work- 

 ing out to their logical conclusion. The question of pleomorphism is 

 more or less begged, but we gather that Dr Migula is not so strong 

 an opponent of the theory as we were led to believe by his earlier 

 writings. The pros and cons are at any rate retailed with admirable 

 fairness. The third section is concerned with the discussion of chiefly 

 physiological characters and various biological criteria of species. 



On the whole, the author and his readers are to be congratulated 

 on this first instalment of the work. The plates are very good, and 

 the bibliography at the end of each chapter exhaustive and exact. 



Another Work on Bacteria 



VORLESUNGEN UBER Bakterien. By Dr Alfred Fischer, a, o. Professor der Botanik 

 in Leipzig. 8vo, pp. viii + 186, with 29 figs. Jena : Gustav Fischer, 1897. Price, 

 4 marks. 



Dk Alfred Fischer's book does not need the apology he makes for 

 its publication in his preface ; a book on non-pathogenic bacteria, or, 

 more strictly, one from which medical bacteriology is entirely excluded, 

 would supply a real want, and the work in question might have 

 answered this purpose if the subject had been given fuller treatment 

 in a less popular Ibrm. It is very good as far as it goes, but, like 

 Oliver Twist, we ' ask for more,' and it is to be hoped that in a second 

 edition, which is sure to be called for, Dr Fischer will remedy this 

 defect, and expand his modest volume into a work at once comprehen- 

 sive and detailed enough to satisfy the demands of the researcher as 

 well as of the student. The author writes very clearly, and is to be 

 congratulated on the exactness of his terminology. As an example of 

 his accuracy in description, he confines his use of the word ' Faden ' to 

 strictly filamentous forms, whereas nine out of ten writers habitually 

 apply this term — or its English Imcteriological equivalent ' filament ' — 



