608 



SCIENCE. 



[N. S. Vol. XII. No. 303. 



The Bryophytes are dismissed with a short 

 chapter which is in harmony with the fact that 

 they constitute one of the least-known groups 

 among fossil plants. 



Attention appears to have been concentrated 

 chiefly upon the vascular plants, of which the 

 author presents a well-chosen selection of types 

 and among which he seems well at home. The 

 most noteworthy feature of this section of the 

 work, and one which gives it special promi- 

 nence in advance of previous publications, 

 is the recognition for the first time, of the re- 

 cently established Cycadofllicinse which marks 

 the most important advance in paleobotany 

 within recent years, and at once indicates the 

 nature of the data which a further study of 

 fossil plants may be expected to contribute to 

 our knowledge of the evolution of plant life. 



The value of the book is greatly enhanced 

 for the purposes of the working botanist or the 

 student, by the superior character of the illus- 

 trations. Taken either by itself or in connec- 

 tion with Seward's more elaborate work, which 

 it largely supplements, it affords a hand book 

 of considerable utility. 



D. P. Penhallow. 



Montreal, Sept., 1900. 



La speleologie, ou science des cavernes. Par E. 

 A. M ARTEL. I volume, 8 vo., pp. 126, avec 

 10 figures. Prix 2 francs. Collection Scien- 

 tia Serie Biologique, No. 8. (Georges Carre 

 et C. Naud, Editeurs, 3, rue Racine, Paris.) 

 A series of small volumes is being issued under 

 the direction of MM. Milne-Edwards, Gaudry, 

 Filhol, Balbiani, and other members of the In- 

 stitute of France ; one of the most recent of 

 them being a hand- book on caverns and their 

 contents. Its title, 'La speleologie,' is coined 

 from two Greek words, and means the Science 

 of Caverns. This term is an improvement on 

 the German ' Hoehlenkunde,' long in use in 

 Austria, for the reason that the latter does not 

 recognize the scientific claim on which emphasis 

 is now laid ; ' kunde ' being the synonym of 

 intelligence, or news, rather than of a classi- 

 fied knowledge. La Societe de Speleologie, of 

 which M. Emil6 Riviere is now president, and 

 M. Edouard A. Martel the general secretary, 

 is in the sixth year of its existence, numbers 

 many eminent scientists among its members. 



with its headquarters at No. 7 rue des Grands- 

 Augustins, Paris, whence it issues a regular 

 bulletin telling the latest news from all parts of 

 the known subterranean world, and publishing 

 special contributions of scientific value. Im- 

 portant service has thus been done to geolo- 

 gists, archeologists, zoologists, hydrologists, 

 mining engineers and hygienists. M. Martel 

 has for many years devoted his summers to the 

 exploration of caves in France, Spain, Greece, 

 Switzerland, Austria, Belgium, Great Britain 

 and elsewhere ; and no man is better qualified 

 than he to treat of the Science of Caverns, as 

 he has so successfully done in the work under 

 consideration. 



' La speleologie ' is divided into sixteen chap- 

 ters. The fix'st chapter defines terms, corrects 

 certain errors and prejudices, traces the history 

 of under-ground exploration, gives a succinct 

 bibliography of cave literature for a century, 

 'and indicates the many ways in which this 

 branch of study has aided mankind. The 

 second chapter deals with the causes producing 

 caverns ; which are mainly, first, pre-existing 

 fissures in the rocks, due to earthquakes, vol- 

 canic eruptions, and other means by which the 

 earth's crust has been rent asunder ; and sec 

 ondly, rain-water, charged with acids from the 

 atmosphere and the soil, which seeks the frac- 

 tures, faults and diaclases thus made, and en- 

 larges them by erosion, corrosion, and hydro- 

 static pressure. This triple process is more fully 

 explained in several successive chapters. Cor- 

 rosion is exemplified by the destruction of gyp- 

 sum and rock salt, and other soluble formations. 

 Evidences of erosion abound in marine grottoes 

 and volcanic caves. Columns of water weigh- 

 ing many atmospheres often stand in deep pits, 

 or flow through secret conduits, bringing tre- 

 mendous pressure upon the rocky strata before 

 which they must yield. 



The author deplores the prevalent confusion 

 of nomenclature employed to describe the phe- 

 nomena and results of aqueous agency. On 

 pages 32 and 33 he spreads before the reader 

 an elaborate table of the names by which pits, 

 chasms, and other exterior and interior open- 

 ings are designated in diSerent countries of 

 Europe and America ; also offering suggestions 

 as to unification or simplification of terms. 



