94 



BOOK NOTICES. 

 ' Synopsis of the Bacteria and Yeast Fungi.'— By w.B. Grove, B. A. 



(London : 1 884, Chatto and Windus.) 

 Professor Cohn's group Schizophytas includes Phycochromaceae and Schizo- 

 mycetes ; to this union the author dissents on the ground of important physiological 

 differences, the most noteworthy of which depends on the presence of chlorophyll 

 in the former, while in the latter it is entirely wanting. Morphologically the two 

 groups closely agree — so much so that, to prove the preconceived idea of their dis- 

 tinctness, a physiological character, the result of the diverse conditions under 

 which they exist, is acknowledged as the crucial test. In Phanerogams achloro- 

 phyllose plants abound, but morphological agreement with chlorophyllose forms is 

 considered sufficient to justify both being included in the same family, as in the 

 Scrophulariacete. Is this a mistake, or is it consistent with science to accept both 

 views ? Professor Wright, in a paper on a new species of Parasitic Green Alga 

 (Trans. Royal Irish Acad., vol. xxv., pt. viii., 1878), describing a new parasitic 

 green alga — Chlorochytrium Cohnii — states that it usually contains bright green 

 chlorophyll, and is thus enabled to support itself by the deoxidation of carbonic 

 dioxide ; but sometimes transitional forms occur, leading up to individuals entirely 

 destitute of chlorophyll. These latter, according to accepted ideas, require organic 

 food, and are, both from a morphological and physiological view, true fungi. 

 Dr. Wright accounts for the parasitism of the green alga, which is met with in the 

 thallus of various species of Sc/iizojtema, by supposing it to be descended from a 

 fungus, which, owing to the differentiation of a portion of its protoplasm into 

 chlorophyll, is rendered independent of organic food, still retaining the original 

 habitat, the colourless form being a retrogression to the primitive type. Without 

 for a moment insisting that, because this transmutation has been observed in a 

 single plant, it necessarily follows that it must be universal ; yet we believe that 

 it does not tend to strengthen the value of chlorophyll as a distinction between 

 Fungi and Algae. The definition of a species, even among the higher forms of life, 

 is no easy matter, yet the student of a special group must, we presume, have — at 

 least for the time being — a more or less settled idea on that subject, to enable him 

 to proceed with systematic and morphological investigations. What Mr. Grove's 

 idea is on this point we have failed to discover. On page 4, after stating his 

 opinion that the number of species is far smaller than Cohn's classification would 

 lead one to judge, says, 'For many of these species are very probably only forms 

 which have been differentiated by the influence of various external agencies, and 

 have become more or less constant.' On page 78, after stating Nageli's' assertion 

 that there were no real species among the Schizomycetes, we read: — ' Much of the 

 disputation on this topic of "species" arises from the fact that many persons can- 

 not readily conceive a species in the new light which the Darwinian theory has 

 thrown upon it. There can be no doubt that new species not only may, but 

 actually must, be making at the present moment.' And, finally, to illustrate the rapid 

 progress made by the author on the subject of the evolution of species since writing 

 page 4, on page 79 he states :^ — -'It follows that we must consider as a species any 

 form or group of forms which, under present conditions, can be clearly distinguished 

 from all other forms, even though we may know that, if the environment were 

 changed, the species would change too.' The systematic part of the book is excel- 

 lent, and the illustrations numerous. A second edition, which in the case of a book 

 so indispensable to mycologists, brewers, and microscopists generally, must soon 

 be called for, will enable the author to incorporate the important researches of 

 Koch on the Cholera Bacillus, and of Zukal on the genetic connexion between 

 Bacteria and Alg£e. Students would be pleased to see Appendix B supplemented, 

 considering the importance of staining in the detection and discrimination of 

 species. — G.M. 



>co< 



The Honey-bee: its nature, homes, and products.'-By w. H. 



Harris, B.A., B.Sc. (The Religious Tract Society; no date.) 

 This book contains a comprehensive and lucid account of its subject, written 

 in an interesting style, and accompanied by numerous woodcut illustrations. No 

 aspect of the subject, whether historical, scientific, or practical, appears to have 



Naturalist, 



