January 4, 1900] 



NATURE 



2 19 



(nitrate) added to the soil, or, as occurs in Leguminosas, 

 in the form of atmospheric nitrogen, fixed for their as- 

 similation by the symbiotic bacteria at their roots. 



Chemotropism, or the effect of chemical agents upon 

 the direction of growth, and heliotropism (phototropism), 

 or the effect of light upon the direction of growth, both 

 receive their due share of attention. The effect of water 

 upon growth is treated separately from that of other 

 chemical agents, this amount of attention being accorded 

 it on account of its immense importance — especially in 

 plants — in the process. The effects of contact with solids 

 and that of molar agents in general are duly considered, 

 and the chapter devoted to them includes subjects so 

 diverse as the results upon the growth of bacteria by 

 violently shaking the vessel containing them, the ten- 

 dency of twining stems and tendrils to grasp the solid 

 objects with which they come in contact, the effect of 

 wounds upon the growth of plants, and even the effect of 

 flowing water in influencing the direction of growth. The 

 effect of gravity upon the growth of sessile organisms 

 (geotropism) and the results obtained by neutralising this 

 effect by the employment of the klinostat is also con- 

 sidered, and illustrated by numerous diagrams. The 

 effect of atmospheric electricity in increasing the rate of 

 growth was supposed to be demonstrated by the experi- 

 ments of Grandeau, who reared two similar plants — one 

 in the- open, and the other with an enclosure of wide- 

 meshed wire netting — with a marked balance in favour of 

 the one which was exposed freely to the influence of any 

 electricity which might be present in the atmosphere ; but 

 others have obtained negative or discordant results, 

 - The effect of heat in influencing the growth of organ- 

 isms is familiar to every biologist, and Dr. Davenport 

 illustrates it by numerous tables and charts taken from 

 observations upon both plants and animals. It is indeed 

 impossible here so much as to enumerate all the different 

 aspects from which the subject of growth has been 

 studied, and to which reference may be found ; and 

 although the book does not profess to be anything more 

 than a compilation, and, in fact, contains no matter which 

 is entirely original, it is that sort of compilation which 

 will be of most use to the student of biology, as indicating 

 to him where he may at once come across the work which 

 has been done in each department of the subject of 

 which it treats. That the information yielded should 

 include everything upon so vast a subject is too much to 

 expect in a book of less than five hundred by no means 

 closely printed pages, and, in fact, one occasionally 

 misses a reference to work of no little interest and im- 

 portance, such as that of Ringer upon the influence of 

 mineral salts upon the growth of tadpoles, and of 

 Romanes upon the comparative effects of flash light and 

 steady light in producing phototropism in seedling 

 plants. Neither is the subject of the influence of drugs 

 considered at anything like the length which its import- 

 ance seems to deserve. Nevertheless, for the reasons 

 indicated, and because the book is a painstaking and, 

 on the whole, a successful attempt to furnish a connected 

 account of an important branch of experimental mor- 

 phology, it will be welcomed by the many workers who 

 are devoting themselves to the pursuit of this interest- 

 ing class of investigation. 



NO. 1575. VOL. 61] 



A BOOK ON MOUNTAINS. 

 Die hochgebirge der Erde. Von Robert von Lendenfeld. 

 Mit titelbild in Farbendruck 148 Abbildungen und 

 i; Karten. Pp. xiv -f- 532. (Freiburg im Breisgau : 

 Herdersche Verlagshandlung, 1899.) 



THIS is a most conscientious piece of bookmaking. 

 The author appears to have read and made a. 

 summary of all the more important descriptions of the 

 mountain masses of the globe. Beginning with a sketch 

 of the physiography of mountains, their development and 

 sculpturing, he passes on to describe them chain by 

 chain. As he has himself travelled much, he can often 

 speak from personal experience, while the numerous and 

 generally excellent illustrations enable the reader to 

 realise the different types of scenery. Reproductions of 

 photographs are used in most cases, but occasionally,, 

 of course, copies of engravings, variable in quality, were 

 alone available. Some, both of the one and the other^ 

 have done duty before, and a few perhaps may be more 

 attractive to the general than to the scientific public. 

 Pictures, for instance, of climbers in a mist seem more 

 appropriate to a book of travels, and some of those re- 

 presenting mountain plants or animals are hardly such 

 as to enhance the value of the book. Attractive also 

 as are all Mr. E. T. Compton's sketches, we cannot but 

 feel that in a treatise of this kind reproductions of photo- 

 graphs would have been better, for accurate delineation, 

 is sometimes sacrificed to artistic sensibility. This is 

 especially true of the drawing of the Grivola on p. 128,. 

 in which we have not found it easy to make out the 

 topography. These, however, are matters of opinion. 

 The book contains a vast mass of information, brought 

 down to the latest possible date, and collected with a 

 thoroughness and accuracy truly German. 



The book also exhibits one or two defects, which 

 perhaps, like its merits, are related to its birth-place. 

 In the treatment of the subject we are conscious of some 

 want of lucid arrangement and of a comprehensive grasp. 

 In regard to the former, a brief outline of the contents 

 may perhaps best indicate our meaning. It begins with 

 a short sketch of mountain building and sculpturing, 

 followed by a glance at the characteristic flora and fauna : 

 a subject so wide that any details can only be fragmentary^ 

 and we should have preferred to pass it by in a few 

 paragraphs which stated the general principles by which 

 the life distribution has been determined. The author 

 then commences, at the seventieth page, his sp^ecial de- 

 scriptions with the mountains west of the Mediterranean, 

 from the Atlas to the Pyrenees. Thence he passes on to 

 the Alps, which are treated, perhaps not unjustifiably, at 

 rather disproportionate length, and then in another 

 section we jump from Sardinia and Corsica to the 

 Apennines, run along the Carpathians to the Balkans, 

 make a leap to the Caucasus, and finally land with the 

 ark on Ararat. Next comes the radiating group of giant 

 chains in Central Asiaj'of which some of the less known are 

 very well described. In the next section, after a very brief 

 glance at the northern mountains of Eurasia in general^ 

 we are transported to Spitsbergen and Iceland, and then 

 restored to the mainland in Scandinavia and the Urals. 

 After that we wander to Central and Southern Africa, 



