7i8 SCIENCE PROGRESS 



low and that the relative humidity of the atmosphere at alpine altitudes is not 

 low but fluctuating ; and the causes promoting excessive transpiration are rare- 

 faction of the air coupled with intense solar ra.d\a.t\on, periods of extreme atmo- 

 spheric dryness and winds. Moreover, attention should be directed to the 

 retardation of water-absorption associated with coldness of the soil during night- 

 time and in the shade during day-time. Again, in treating of the special 

 habitats of alpine plants, Mr. Arber writes : " It may be assumed that such 

 species are specially suited to the particular conditions under which they live 

 and are not adapted to circumstances which prevail elsewhere." Apart from the 

 vague use of the word " adapted," it is not pointed out that one most important 

 factor included under the head of " circumstances " is competition and that many 

 extreme alpine species can be successfully cultivated in the lowlands, whilst 

 some naturally grow near the seashore. Throughout the book " adaptation " is 

 somewhat too freely invoked as a mystic deus ex machina by which to explain 

 features whose nearer cause lies in direct action of the environment or in untested 

 or unknown influences. A climax is reached when the author writes : " It is 

 conjectured that the earliest primitive flowers were wind pollinated, but owing 

 to the probability that they were soon visited by insects, who robbed them of their 

 pollen, the plants appear to have determined that, if they must suffer robbery, 

 they might as well make use of the insects in some way, and consequently they 

 hit on the happy idea of making them the pollen distributors. So successful was 

 the move in this direction, that it quickly became ' fashionable ' to adapt the 

 flowers especially to insect visitors." Such anthropomorphic misrepresentation 

 cannot be too strongly condemned and is somewhat of a shock when coming 

 from a competent scientific author, for it is not passively unscientific but is actively 

 anti-scientific. The hope may be expressed that a new edition of the book will 

 soon be called for and that the author will then so retouch the text as to make 

 it match the admirably selected and executed illustrations and the general 

 soundness of the subject-matter. 



History of the Theories of .ffither and Electricity. By E. T. Whittaker, 

 F.R.S. [Pp. 475 -\- xiii.] Dublin University Press Series. (London : 

 Longmans, Green & Co., 1910. Price \2s. bd. net.) 



The beginning of the twentieth century, witnessing, as it has, the passing away 

 of Stokes and Kelvin, the last of the older school of great physicists and the rise 

 and rapid development of a new school under the work and teachings of J. J. 

 Thomson and his pupils, forms a fitting time to review the theories by which 

 attempts have been made to explain the phenomena connected with light and 

 electricity. Until the seventeenth century, the only influence which was known 

 to be capable of passing from star to star was that of light. Newton added to 

 this the force of gravity and since his time, the power of communicating across 

 vacuous space has been shown to be possessed by electric and magnetic attrac- 

 tions. The vehicle of this conveyance of energy is the cether, occupying all but 

 that infinitesimal fraction of space which is occupied by ordinary matter. Hence 

 arises the problem as to the relation between tether and matter, a problem not 

 yet completely solved. The history of this problem, beginning with Descartes in 

 the earlier half of the seventeenth century and ending with a brief account of the 

 latest work of the Cambridge school, has been admirably traced in the book under 

 notice and the author is to be congratulated highly on the painstaking manner in 

 which he has compiled a very interesting work. 



