NATURE 



433 



THURSDAY, SEPTEMBER 4, 1884 



FUNGI AND BACTERTA 

 Vergleichende Morphologie und Biologie der Pilze, Myce- 

 tOBoen, 11 nd Bacterial. By A. De Ban". (Leipzig: 

 Engelmann, 1S84.) 



THOSE of us who have been awaiting the publication 

 of a new edition of De Bary's " Morphologie und 

 Physiologie der Pilze, Flechten, und Myxomyceten " of 

 eighteen years ago, will be neither surprised nor disap- 

 pointed to find that the author has felt compelled to 

 change the title as well as to effect such important altera- 

 tions in the text that the book is not only virtually but 

 really a new one. This is, moreover, extremely satis- 

 factory, since it shows that the province of mycology has 

 been extended during the period named. How far this 

 extension is due to the labours and influence of the writer 

 of the book before us is well known to all botanists. 



In some respects the general plan of the old book has 

 been followed, and many of the woodcuts have been 

 retained ; but the large and at that time important section 

 on the reproductive organs in the previous edition is no 

 longer to be found as a separate part of the present book, 

 the results of more recent investigations having com- 

 pletely altered the position of the question as to the 

 sexual reproduction of the Fungi. This fact is of course 

 also a motive in the very different views on classification 

 held by the author now, as contrasted with those pub- 

 lished in the earlier book. These and the addition of the 

 Bacteria as an entirely independent group of organisms, 

 are among the principal points of difference in the general 

 plan of the book. That they are by no means the only 

 changes in plan, however, is to be seen at a glance on 

 comparing the two editions. 



The present work is divided into three " Parts," devoted 

 to the Fungi, the Mycetozoa (Myxomycetes), and the 

 Bacteria respectively. Under the Fungi proper, there 

 are three chapters devoted to " General Morphology," 

 including Histology, the Segmentation of the Thallus, 

 and the Morphology of the Spore ; the latter being very 

 fully treated of, and many new facts being added. The 

 second part deals with the groups of Fungi themselves, 

 and their evolution ; the theoretical portions of Chapter IV. 

 being extremely comprehensive and clear, and touching 

 upon matters of the widest biological interest. Chapter V. 

 deals with the various groups comparatively and in detail. 

 Starting with the Peronosporea?, the author follows the 

 series through the main Ascomycetous series to the Ure- 

 dinete, in conformity with his now well-known views on 

 the classification, dealing by the way with those groups 

 which diverge from the main series or are still doubt- 

 fully situated. 



The third part of the main subject (Chapters VI. and 

 VII.) is devoted to the physiology of the Fungi, including 

 the phenomena of parasitism and the commensalism of 

 the Lichens, and bringing us through by far the larger part 

 of the book. 



The Mycetozoa (Chapters VIII. and IX.) occupy nearly 

 40 pages of most interesting matter, including a discussion 

 as to the position of these remarkable organisms, and an 

 account of what is known as to their physiology. 

 Vol. xxx. — No. 775 



The Bacteria or Schizomycetes are dealt with separately 

 and in detail at the conclusion of the book. Chapter X. 

 is devoted to their morphology, and discussions as to their 

 position in the system, and the meaning of " species." A 

 sharp comparison of the extreme views on this subject is 

 dealt with shortly, and in the author's characteristic style. 

 Probably the most fascinating chapter in the book 

 (unless Chapter IV. be excepted) is the last one, dealing 

 with the physiology and life-history of the Bacteria, and 

 of course touching the subjects of pathology and adapta- 

 tion to different media and conditions with a master 

 hand ; and it will be an enormous boon, and should be a 

 stimulus, to have the facts as to the resistance of germs, 

 conditions of development, &c, of these important organ- 

 isms sifted by an author of such wide experience. 



Enough has been said to show that the present book is 

 rather to be considered as a new work than as a second 

 edition of the " Morphologie und Physiologie der Pilze, 

 &c." But it is not only in that so much new matter has 

 been added and a different arrangement been found 

 necessary that this book differs from the former one ; the 

 theoretical portions have also undergone changes even 

 more striking and important than the statements of fact. 

 To put the subject in the shortest possible form : — While 

 the then recent discoveries of Pleomorphism and the repro- 

 ductive organs by Tulasne and De Bary were leading myco- 

 logists to suspect that a reproductive process exists in the 

 case of all the higher Fungi, the prominent doctrine, so 

 to speak, in the older work was in accordance with the 

 expectations which had been aroused. Nevertheless, no 

 better monument to the sagacity of the author could 

 perhaps be suggested than his careful statement of the 

 case of the sexuality of the Ascomycetes, even in 1866. 



It is well known now that the investigations of the last 

 eighteen years have gone to show that not only do the re- 

 productive organs gradually become simpler and finally 

 disappear in the higher Fungi, but that the physiological 

 processes intrusted to them fade away even earlier — the 

 former depending on the latter, in fact. This doctrine of 

 Apogamy, established by De Bary, of course profoundly 

 affects the work before us. The whole subject. of Pleo- 

 morphy is also now in a far better position, and we 

 strongly recommend all young botanists to read and 

 mark well the introduction (Chapter IV.) to the second 

 section of this book, which contains much just and 

 trenchant criticism on all these matters, and on past 

 mistakes and future dangers connected with them. The 

 notes on terminology should also be well pondered by the 

 more reckless. 



It would take too long to enter further into details as to 

 the classification adopted. It may suffice to point out that 

 the Pcronosporea: (and Ancylistea and Monotdepharis), 

 Saprolegnia, Zygomycetes, and Entomophthorece are 

 treated as four groups, which, on account of their rela- 

 tions to the Algae, may be comprehended as the Phyco- 

 mycetes. The main line of the Phycomycetes leads us to 

 the Ascomycetes, and, further, to the Uredinece. The 

 treatment of the enormous mass of A scomycetes is mas- 

 terly in the extreme, and testifies better than anything 

 else to the progress made in the biology of these Fungi 

 during the last twenty years. The groups mentioned are 

 regarded as the " Ascomycetous series." 



As diverging groups, or such the position of which is 



