August 4, 19 10] 



NATURE 



135 



these rjesearches would appear to fall short of their 

 object in that they ignore the foundations and prin- 

 ciples, and even the existence, of a science of stereo- 

 chemistry, founded so long ago as i860 by Pasteur for 

 chemists — and biolojjists. In his two lectures "On 

 the Asymmetry of Naturally Occurring- Organic 

 Compounds," Pasteur wrote : — 



■'Who can foresee the org-anisation that livint; 

 matter would assume if cellulose were Ijevo-rotatory 

 instead of being dextro-rotatory, or if the lavo-rota- 

 tory albumens of the blood were to be replaced by 

 dextro-rotatory bodies ? These are mysteries which 

 call for an immense amount of work in the future, 

 and to-day bespeak consideration in the science." 



Trophoblr:f:t, which, by means of its intracellular 

 ferments, pulls down the living " laevo-rotatory albu- 

 mens of the blood," cannot itself be made up of such 

 bodies, but by all the canons of stereo-chemistry must 

 consist of dextro-rotatory ones. B. 



PLAXT-LIFE I\ THE BALKANS. 

 Die Vegetationsvcrhiiltnisse der Balkanldnder 

 {Mosisclie Lander). By Prof. Lujo .'\damovic. Pp. 

 xvi+567; with 49 plates, 11 text-figures, and b 

 maps. (Leipzig : W. Engelmann, 1909.) Price 

 32 marks. 



THIS bulky volume on the vegetation of the Balkan 

 district is the eleventh in the series of mono- 

 graphs of plant geo.eraphy, edited, under the title 

 '■ Die Vegetation der Erde," by Profs. A. Engler and 

 O. Drude. The district includes Servia, Bulgaria, 

 East Rumelia, North Thracia, and North Macedonia, 

 and the volume therefore forms a companion one to 

 Dr. Beck von Mannagetta's account of the vegetation 

 of the Illyrian district, comprising the western part 

 of the Balkan peninsula, which formed the fourth 

 volume of the same series. 



In an introductory chapter. Dr. Adamovic gives a 

 sketch of the history of the botanical exploration of 

 the Balkan territory. This began in earnest with the 

 work of Josef Pancic on the flora of Servia (1846- 

 88), which has been supplemented by that of 

 numerous other botanists, especially of Dr. Adamovid 

 him.self, who has worked continuously from 1890 on- 

 wards. The bibliography includes a long list of 

 papers. 



The subject-matter of the book falls under four 

 sections. The first is a sketch of the physical 

 geography of the area, in which chapters are devoted 

 to the orographic, hydrographic, geognostic, and 

 climatic conditions respectively. Climatic conditions 

 are regulated by the position of the area under con- 

 sideration, in the interior of a broad peninsula bordered 

 only by small seas, while in the south high mountain 

 ranges — the Rhodope system in the south-east and 

 the Dinaric system in the south-west — hinder the 

 approach of warm winds, and in the north the cold 

 northern winds find a free entrance. Three climatic 

 zones are recognised— Ci) the West Moesic, which 

 stretches westward from the two mountain systems 

 just mentioned, and is characterised especially by the 

 NO. 2127, VOL. 84] 



prevalence of northerly and easterly currents ; a cold 

 winter is follov.-ed by a cool and damp spring, a fairly 

 warm summer, and usually a warm and fairly long 

 autumn ; (2) the East Mcesic zone, to the north of the 

 Balkan range, characterised by easterly currents and 

 a climate similar to that of southern Russia ; and (3) 

 a southern zone, including almost the whole of East 

 Rumelia, Thrace, the southernmost part of "Alt 

 Servia " and North Macedonia, which has a climate 

 approaching that of the Mediterranean region. 



The second section deals with the vegetation, and 

 is divided into three parts, in the first of which, 

 " CEcological Factors," the author discusses the in- 

 fluence on the plant-life of external influences. Such 

 are the so-called tectonic factors — disposition of land, 

 mountain, plain, and valley, difference of exposure 

 and the like, composition of the soil — chalk, serpentine, 

 volcanic sand, or salt. A good deal of matter of 

 general biological interest is included in the chapter 

 dealing with climatic factors and the effect of many 

 animals and plants themselves on the vegetation. 

 The remainder of the section is an account of the 

 various plant-formations; these are arranged under 

 two heads, representing the two great constituents, 

 those characteristic respectively of the Mediterranean 

 and Central European floras. Under the former are 

 included the " Ornus-Mischlaubwald," the mixed 

 deciduous forest which forms a characteristic high- 

 wood on the hilly and submontane districts of the 

 Balkan peninsula ; the diversity and abundance of its 

 constituents render it comparable with no other 

 European formations. Here also is the horse-chest- 

 nut-formation and the pseudo-maquis, the latter 

 analogous to the evergreen bush-formation or maquis 

 of the Mediterranean area, but adapted to a neces- 

 sarily shorter vegetative period ; the most frequent 

 and widely distributed element of the pseudo-maquis 

 is Juiupenis oxycedrus, while the arborescent juni- 

 periis exceha, the box, and PhiUyrca vicdia are char- 

 acteristic elements. These and other formations com- 

 prise the arborescent and bush vegetation, besides 

 which is a series of steppe, rock, salt-marsh, aquatic, 

 meadow, cultivated land, and other formations. The 

 third and largest portion is an account of the plant- 

 formations of a Central European type, the submon- 

 tane woods of oak, sweet chestnut, and black pine, the 

 mountain woods of fir, pine, spruce (Picca omorica), 

 birch, and beech, the bush-formations, the rock, 

 steppe, meadow, marsh, and aquatic formations, and, 

 finally, the subalpine and alpine. 



In the third section the author suggests zonal 

 arrangements, both horizontal and vertical, of the two 

 great type-groups of the vegetation ; and in the fourth 

 and last section attempts to trace the developmental 

 history of the flora by a consideration of the frag- 

 mentary evidence afforded by the plant remains from 

 successive geological strata. 



A notice of Dr. Adamovi^'s exhaustive and pains- 

 taking survey of the vegetation of the Balkan area 

 would be incxDmplete without an appreciation of the 

 plates, most of which are reproduced from photo- 

 graphs taken by the author. A. B. R. 



