60 Bibliographical Notices, 



Fossil Plants as Tests of Climate. By A, C. Seward, M.A., F.G.S., 

 &c. 8vo. 151 pages. C. J. Clay & Sons : London. 



Tnis is the "Sedgwick Prize-essay" for the year 1892, and its 

 subject has been well chosen (1) as being worthy of, and indeed 

 requiring an earnest and corapi-ehensive study of both recent and 

 fossil botany by the essayist, and (2) as a subject, a broad view of 

 which, based on trustworthy details, is a desideratum "with geolo- 

 gists. 



As is due to observers in the past, though results of value were 

 scanty even in the early part of the present century, careful refer- 

 ences to early works, and critical notes on the facts and opinions 

 therein stated, are given in the " historical sketch " (pages 1-32), 

 which, like the Essay itself, is based on Mr. Lester F. Ward's 

 'Sketch of Palseobotany,' in the 'Fifth Annual Report of the U.S. 

 Geol. Survey ' for 1883-84, pages 363-453 (1885), and extended to 

 the present time. 



A general knowledge of the present distribution of plant-families, 

 and of their relation to climatal conditions, must precede the con- 

 sideration of the coexistence of the ancient and extinct floras with 

 the successive geographical conditions of bygono lands and their 

 changing climates ; Chapters II. and III., therefore, comprise per- 

 tinent remarks by trustworthy authors treating of the distribution 

 of plants, with reference to geography and topography, height of 

 land above the sea-level, ihe nature of the soil, and, lastly, low tem- 

 peratures, as in Greenland, Grinnell-land, Alaska, and Ilussian 

 Laplond. 



In Chapters lY. and V. the influence of external conditions upon 

 the macroscopic and microscopic structures of plants is considered, 

 on the basis of published reports with respect to the habit and size 

 of plants in relation to climate ; the form, position, and structure of 

 leaves ; their minute structure and its relation to external condi- 

 tions ; water-plants ; acclimatization and naturalization ; and minute 

 anatomy of fossil plants ; also the annual rings in recent and fossil 

 plants. 



" By far the most interesting lessons in questions of ancient 

 climates have been taught by fossil plants in the high northern 

 latitudes of the Arctic regions," hence Chapter YI. comprises the 

 notices and remarks made by various observers on (1) the Devonian 

 and Carboniferous plant-remains of Bear Island, Spitzbergen, and 

 Melville Island. (2) Upper Carboniferous of Siberia, Novaya 

 Zembla, and Spitzbergen. (3) Jurassic of Spitzbergen and Melville 

 Island (?). (4) Cretaceous of Spitzbergen and Greenland. (5) Tei'- 

 tiary of Spitzbergen, Iceland, Greenland, Grinnell-land, Bathurst 

 Island, Banks' Land, Prince-Patrick Island, and Mackenzie Iliver. 

 (6) Quaternary of Spitzbergen. 



So far as the fossil plants of the Arctic regions have been studied 

 0. Heer considered that they give no evidence of any difference in 

 the temperature of the Polar Ilegions from that of Central Europe ; 



