400 JOURNAL OF THE EOYAL HORTICULTURAL SOCIETY. 



BOOK KEVIEWS. 



"Studies in Fossil Botany." By D. H. Scott, M.A., Ph.D. Second 

 Edition. Vol. ii., 8vo., 322 pp. (Black, London, 1909.) 5s. net. 



Part I. of the second edition of Dr. Scott's work has already been 

 reviewed in this Journal, and it was then pointed out that, owing to the 

 rapid progress of our knowledge of fossil botany since 1904, Dr. Scott 

 had been obliged to rewrite rather than revise his book. Most of the new 

 matter appears in Part II. Chief interest attaches to the very clear 

 account which is given of the Pteridosperms or fernlike seed-bearing 

 plants and to the account of the Mesozoic Gymnosperms. The study of 

 these groups of fossil plants has not only bridged over huge gaps in the 

 history of the Vegetable Kingdom but has also led to a clearer under- 

 standing of the relationships of existing plants to each other. In other 

 words, such study has done much towards " the completion of the natural 

 system." 



The author commences with a very complete account of Lyginodendron 

 Oldhamium, now the most completely known of all fossil plants. He 

 describes the way in which the stem (Lyginodendr&n), the root (Kaloxylon 

 Hookeri), the petiole (Bacliiopteris aspera), the frond impression (Spheno- 

 pteris H owing hausi), the microsporangia (Crossotheca Honinghausi), and 

 the seed (Lagenostoma Lomaxi), have been proved to belong to one and 

 the same species. From this plant, a complete typical Pteridosperm, the 

 author proceeds to describe other Pteridosperms, and then fernlike plants 

 which have not yet been proved to be seed-bearing, but can still be 

 provisionally classed as " Cycadofilices." The Cordaitales, including the 

 Cordaiteae and forms which link the latter to the Pteridosperms, are next 

 taken. Careful treatment is then given to the Mesozoic Gymnosperms. 

 The Bennettiteae are chiefly interesting on account of Dr. Wieland's 

 wonderful discoveries. The hermaphrodite "flower" of Cycadeoidea 

 ingens brings the origin of the Angiosperms within the region of scientific 

 discussion. The author proceeds to deal with the fossil history of the 

 Coniferae and examines fossil evidence for or against Professor Seward's 

 theory that the Araucarieae are members of an ancient group of Gym- 

 nosperms descended from Lycopod ancestry. He agrees with Seward as 

 to the antiquity of the Araucarieae and as to their primitive nature, but 

 concludes that their affinities lie with the Cordaiteae rather than with 

 Lycopods. Dr. Scott concludes with a long and extremely interesting 

 chapter of " general results," in which he discusses fully the chief questions 

 of classification and descent which have been affected by evidence afforded 

 by fossil botany. He deals critically with the results of recent morpho- 

 logical investigation of living species whenever such results either support, 

 or seem to contradict, conclusions based upon a study of fossils, and 

 ends by putting forward a provisional scheme for the grouping of vascular 

 plants, recent and extinct, into three main groups : (1) Sphenopsida 

 (Equisetales, Pseudoborniales Sphenophyilales and Psilo tales) ; (2) Lyco- 



