NA TURE 



[November 2, 1905 



found of service in identifying British wild flowers 

 and discovering something about their affinities and 

 the significance of their structure. These volumes 

 have now been completely re-arranged, and the plates 

 have all been newly drawn, so that the revised edition 

 is substantially a new work. In the original books, 

 plants were roughly arranged in the order of the 

 seasons in which their flowers appear, but in the 

 present volumes a more natural grouping is followed, 

 series i. containing representatives of the plant 

 families from the Buttercups to the Composites in- 

 clusive, and series ii. from the Composites to the 

 Grasses and Ferns. This arrangement is much more 

 instructive than the former one; and in connection 

 with the descriptions of family characters given a t 

 the end of each volume it should facilitate the further 

 study of plants in more elaborate works. 



The coloured plates in the two volumes are, with 

 few exceptions, very fine, and will enable the countrv 

 rambler easily to identify the flowering plants he 

 meets. In almost every case the pictures are truer 

 to nature than those in the original volumes, though 

 these left little cause for complaint. The picture, for 

 instance, of Lady's Smock is much superior to that 

 in the old edition; so is that of Germander Speedwell. 

 The Chicory flower, however, is better represented in 

 the old volume than in the new ; and in neither is 

 the illustration of Tamarisk satisfactory. The ideal 

 way to depict flowers for purposes of identification 

 would be to take tri-colour photographs of the flowers 

 and reproduce them by the three-colour process of 

 printing. This method, which has been successfully 

 adopted in the illustration of a few natural history 

 objects, might have been profitably used by Mr. Step 

 instead of lithography. No doubt there are difficulties 

 to be overcome, but they are not very great, and 

 success should attend "the work in which the 

 advantages of colour photography are brought into 

 requisition. But while we await these faithful photo- 

 graphic reproductions, it is good to possess Mr. Step's 

 two pocket guides with their clear descriptions and 

 plates, and we are glad that such attractive books 

 exist to awaken interest in plant life. 



Quiet Hours with Nature. Bv Mrs. Brightwen. 

 Pp. xvi + 271. (London: Fisher Unwin, 1904.) 

 Price 2S. 



Mrs. Brightwen 's books no longer need to be re- 

 commended to beginners in natural history. A fresh 

 collection of her simple and sympathetic accounts of 

 animal and vegetable life as studied and enjoyed in 

 her own garden and park is sure to be welcome to 

 all boys and girls who have once begun to take an 

 intelligent interest in natural objects. All we need 

 say about this volume is that, besides some pleasant 

 papers about her tamed wild animals, including 

 squirrels, field-voles, a rook, and even a stag-beetle, 

 which followed his benefactor across the lawn, it 

 contains others on the trees in her garden and some 

 of the plants in her conservatory, all well calculated 

 to arouse just such an interest in common things as 

 may carry the young reader on to more exact and 

 elaborate studies of nature. The book is charmingly 

 illustrated by photographs and drawings. 



One word of criticism may be allowed. It is surely 

 as well, in introducing voung folks to the study of 

 nature, not to lead them to think that there is an 

 essential difference between the " professional " 

 entomologist or ornithologisl and the ordinary 

 observant field-naturalist; or if there be a real differ- 

 ence, it may be a- well not to emphasise it. On p. 191 

 Mrs. Brightwen quotes a scientific description of the 

 head of Eristalis tenax, with the comment : — " Now I 

 NO 1879, VOL. J^l 



this may be very interesting to a professional entom- 

 ologist, but it does not convey much information to 

 an ordinary reader, and yet this is the scientific de- 

 scription of my drone-flies, interesting creatures which 

 I kept through a whole winter until thev were coaxed 

 into the circle of my winged friends." It is true 

 that the description conveys but little to an " ordinary 

 reader," but a very little 'trouble will make it convey 

 a great deal, and this small amount of trouble, or of 

 instruction if it can be had, is exactly what our 

 young " nature-lovers " should be encouraged to face. 

 As it happens, the example of Eristalis is a good one; 

 for the history of its confusion with the bees is a 

 most interesting one, showing how much delusion 

 may arise, and not only delusion, but myth, merely 

 from the want of a little knowledge of structure. 



Hammlung Schubert, XLII. Theorie der Electrizitat 

 und des Magnetismus. Vol. ii. By Prof. Dr. J. 

 Classen. Pp. ix + 251; with 53 figures. (Leipzig: 

 G. J. Goschen'sche Verlagshandlung, 1904.) Price 

 7 marks. 



This forms the second part of an introductory text- 

 book of electricity and magnetism in which chief 

 stress is laid on the mathematical side. In this 

 volume the Faraday-Maxwell conception of elec- 

 trical phenomena still forms the central idea ; but, 

 since the representation of simple magnetic pheno- 

 mena in terms of a distribution of enerev in a medium 

 presents considerable difficulty from the' mathematical 

 standpoint, the classical conception based on action at 

 a distance is retained, but regarded merely as a 

 mathematical device and not as a physical concep- 

 tion. In the section on electromagnetism the author 

 adopts the special form of equations developed by 

 Hertz in his paper on the fundamental equations of 

 electromagnetism for bodies at rest, and expresses 

 his strong opinion in favour of generally adopting 

 these in all treatises of mathematical physics. 



Only one part of Maxwell's characteristic treat- 

 ment of the subject finds no place here, and that 

 is his demonstration of the connection between the 

 fundamental equations of electricity and the general 

 Lagrangian equations of mechanics. 



Vegetationsbilder. By Drs. G. Karsten and H. 

 Schenck. Third series. Parts i.-iii., containing 

 plates i.-xviii. (Jena : Gustav Fischer, 1905.) 

 Botanists who possess the first two series of the 

 " Vegetationsbilder," or who have had the opportunity 

 of admiring these magnificent series of photographic 

 reproductions, will be glad to see that the third series 

 is rapidly taking shape. The subject of epiphytic 

 flower-gardens arising out of ants' nests, which 

 formed part of a previous number, by Mr. E. Ule, is 

 more fully treated in the first part of this series by 

 the same authority. The ant-gardeners are species of 

 Azteca, most often Azteca Traili and Camponotus 

 femoratus. The plates represent different stages in 

 the formation of the gardens; the plants Which 

 develop from seed brought in by the ants are chiefly 

 aroids, bromeliads, and species of Gesneraceae. In 

 the second part Mr. E. A. Bessey presents a study 

 of the sand-dunes, shifting and stationary, of Russian 

 Turkestan with a vegetation of Calligonum, Salsola, 

 Tamarix, and other xerophytes ; the arboreous Salsola 

 is particularly interesting. The photographs of lava, 

 forming the third part, have been supplied bv Prof. 

 M. Biisgen, Mr. H. Jensen, and Dr. W. Basse. The 

 subjects chosen include the teak forests, an expanse 

 of the lotus, Nehimbium speciosum, a sand-dune 

 bound bv the creeping Spinifex squarrosus, and a 

 bamboo forest. 



