lyo 



NATURE 



[April (> 



I'M 



(Abyssinian). Nevertheless the book under review 

 sums up in small compass much of the interest of 

 northern Nigeria. 



Lclirbuch der allgemeinen Vflanzcn geographic, nach 

 cntwickclungs-gescliichtlichcti tind physiologisch- 

 okoliigischcn (iesichlspmiktcn. Bearbeitet von 

 I'rof. P. Graebner. Mit beitr;i>^en von Prof. 1'. 

 Ascherson. Pp. viii + 303. (Leipzig: Quelle and 

 Meyer, lyio.) Price 8 marks. 



No branch of botany has advanced more rapidly in 

 the last quarter of a century than the study of plant 

 geography or distribution. Althouj^h the foundations 

 were laid by Humboldt (1805), de Candoile (1855), and 

 Grisebach (187^), much of the impetus is due to the 

 influence of the already classical works of Warming 

 and Schimper, and to the valuable contributions by 

 Dr. Engler ; further, the numerous recent papers de- 

 voted to the descriptions of vegetation in all parts of 

 the world have provided additional data for establish- 

 ing general principles. 



Plant geograjjhy presents the two main aspects of 

 distribution in space and distribution in time. The 

 former has received more attention, and provides the 

 sole topic of most books on the subject. Dr. Graebner 

 has devoted a third part of his book to an account of 

 development in past geological ages and in historical 

 times. This provides a serviceable epitome, although 

 some of the statements — as, for instance, the sug- 

 gested aquatic hnbit of the Sphenophyllaceae — are 

 questionable. The discussion of events in the Ter- 

 tiary and Glacial periods leads up to such matters as 

 plant migrations, centres of distribution, origin of 

 new species, variation, casuals, aliens, and colonists. 

 Distribution in space is taken in two sections, of 

 which the first relates to floristic kingdoms, the 

 second to ecological conceptions. The consideration 

 of the subject from these two points of view would 

 serve a useful purpose if the advantage was not dis- 

 counted by the excessive condensation necessitated. 

 The description of causes influencing plant distribution 

 in the present day contains a store of details gleaned 

 from scattered papers, and provides much material 

 for elaboration. Very little space is apportioned to the 

 account of plant formations; their classification is 

 based upon the paucity or richness of the available 

 food supply in the soil. Numerous references to 

 original publications are supplied in the footnotes, 

 which it would seem worth while to collect into an 

 appended classified bibliography. 



The Natural History of Coal. Bv E. A. Newell Arber. 

 Pp. x+i6j. (Cambridge-: University Press. 1911.) 

 Price i.<r. net. 



Within the narrow compass of this little volume, 

 which forms one of "The Cambridge Manuals of 

 Science and Literature," Mr. Newell Arber has con- 

 densed a great amount of solid information with 

 respect to the nature of coal, and much speculation 

 with regard to its probable mode of formation. Per- 

 haps the most notable feature of the work is the 

 emphasis which it lays on the fact that "coal" is 

 merely a group-name, applied popularlv to a number 

 of carbonaceous substances, verv varied in character 

 and doubtless very diverse in origin. No one mode 

 of formation is applicable to all coal. If it can be 

 proved in a particular case that the vegetation from 

 which the coal was originallv formed must have grown 

 on the spot where it is now found, we are bv no 

 means justified in denying that in other cases' the 

 vegetable ddbris mav have been drifted to its present 

 site. " ^ 



The author holds that each group of coal-bearing 

 rocks, even each seam of coal, must be studied and 



NO. 2162, VOL. 86] 



judged on its own merits. The material from whidi 

 coal has been formed he calls " the mother-substance 

 of coal " — an expression not to be confused with the 

 term " mother oJ coal," which has long been applied, 

 perhaps not very appropriately, to the substance known 

 otherwise as mineral charcoal. .Mr. .^rber di'-i 

 with much command of his subject, the char.i 

 lh(! coal-forming vegetation, the mode in whicn iis 

 relics accumulated, and tlie changes to which they have 

 been subjected in the process of coal-making. 



The view which regards the formation of palaeozoic 

 coal as having been comparatively rapid finds favour 

 with the author, whilst doubt is thrown on the popular 

 "peat-to-anthracite th<'<)ry." As to the vexed question 

 of the climate of L"p|)er Carboniferous times, Mr. 

 Arber hesitates, for apparently good reason, to term 

 it tropical. 



Eine Botanischc Tropenreise. Indo-Malayisclic I cge- 

 tationshildi'r und Rciseskizzen. By Prof. G. 

 Haberlandt. Zweite .Auflage. Pp. viii + 296. (Leip- 

 zig : W. Engelmann, 1910.) Price 11.60 marks. 

 There is very little change to note in the present edi- 

 tion of Haberlandt's " Botanische Tropenreise" as 

 compared with the original that was published in 

 1893. A few paragraphs have been inserted here and 

 there, some excellent reproductions frcMii photographs 

 have been added, and three coloured reproductions 

 from water-colour sketches by the author. It would 

 have been unwise to reconstruct the general text, 

 which records the fresh impressions of a first visit to 

 the tropics. The chapters on tropical leaves and trees, 

 lianes, epiphytes, and mangroves are specially instruc- 

 tive, and the bold pencil sketches delineate characters 

 which are not discernible in a photograph. 



Star People. By Katharine Fay Dewey. With illus- 

 tration by Frances B. Comstock. Pp. x+232. 

 (London : Longmans, Green, and Co., 1910.) 

 Price 6s. net. 

 Some of the mythological characters which figure 

 among the constellations are here introduced into 

 a fantastic story. W'e cannot believe that the original 

 legends have been improved by their setting, or that 

 there is anything particularly inspiring in the asso- 

 ciation of stars with nonsense talk and a giggling 

 company. Draco is afflicted with a lisp, and is made 

 to say on one occasion "That'th all right. I gueth 

 I can walk with three girlth. I 'm long enough ! " 

 The constellations are so beautiful and the dramas 

 they represent are so rich in imaginative ideas that 

 we should prefer not to introduce children to either 

 through a story of this kind, which can scarcely be 

 regarded as good literature and is certainly not good 

 science. 



With Nature and a Camera : Being the Adventures 



and Observations of a Field Naturalist and an- 



Animal Photographer. By Richard Kearton. 



Illustrated by 180 pictures from photographs by 



Cherry Kearton. Popular edition. Pp. xvi + 368. 



(London : Cassell and Co., Ltd., 1911.) Price 5s. 



Its re-issue in a cheaper form should increase the 



already wide popularity of this attractive book. The 



character of the work was described in Nature soon 



after its appearance (vol. Ivii., p. 154). 



British Birds in Their Haunts. By the late Rev. 

 C. A. Johns. Twelfth edition, with 16 coloured 

 plates. Pp. xxxii + 626. (London: Society for 

 Promoting Christian Knowledge, 191 1.) Price 55. 

 .\ BOOK which has reached its twelfth edition needs 

 no commendation. It is evident that its clearly ex- 

 pressed descriptions have proved of real assistance 

 to students of bird-life. 



