824  Reviews—Professor A. C. Seward’s Fossil Plants. 
IJ.—Fossiz Puanrs: A Text-book for Students of Botany and Geology. 
By A. C. Sewarp, M.A., F.R.S., Professor of Botany in the 
University, Fellow of St. John’s College, and Hon. Fellow of 
Emmanuel College, Cambridge. Vol. II.’ pp. xxii+-624, with 265 
illustrations. Cambridge: the University Press, 1910 (C. F. Clay, 
Manager, Fetter Lane, E.C.). Price 15s. 
W* gladly welcome the arrival of the second volume of this 
important work, and none the less so that we have waited long 
and patiently for its advent. In the first volume more than 100 pages 
are occupied in general matters introductory to a study of fossil plants 
both from a geological and a botanical aspect. These are followed by 
a chapter on the Thallophyta, embracing all the simplest forms of 
vegetative structures—Diatoms, Coccospheres, Rhabdospheres, and the 
like; Alge, Grvanella, Schizomycetes, Ovulites, Chara, and many 
others. Then come the Bryophyta, Liverworts, Mosses, etc., followed 
by the Pteridophyta, or Vascular Cryptogams, and the Equisetacex ; 
these are continued into and concluded in vol. 11. Here are also 
placed the doubtful fossil forms, the Psilotales. The Equisetites of the 
Secondary rocks and their predecessors, Phyllotheca, Schizoneura, etc., 
of Triassic and Permo-Carboniferous times, are here described and 
figured, and the [quisetales, represented by the numerous forms of 
Calamites of the Coal-measures with their wonderful stem-structures, 
leaves, and spore-bearing cones (strobilites), and Sphenophyllum, upon 
which genus the late Professor Williamson devoted so much patient 
investigation. They form the concluding chapter in vol.1i and the 
opening chapter in vol. 11. Here is also added an account of the spore- 
cone of Cheirostrobus, Scott. ‘These embrace a most interesting group 
of fossil plant-remains in which the structure has been preserved in 
a marvellously perfect manner. 
The two recent genera, Psilotum and Tmesipteris, are usually spoken 
of as members of the family Psilotaceze, which is included as one of 
the subdivisions of the Lycopodiales. It is probable, as Scott first 
suggested, that these two plants are more nearly allied than are 
any other existing types to the Paleozoic genus Sphenophyllum. 
Psilophyton, another rather obscure fossil plant from the Devonian 
and Silurian rocks of Canada, is placed near the foregoing, but its true 
botanical relations are a little uncertain. 
The Lycopodiales, like the Equisetales and Calamitez, present to. 
us plants having recent representatives and also a great and important 
series of fossil genera. ‘‘A general acquaintance with the extinct as. 
well as with the recent Lycopodiales will enable us to appreciate the 
contrast between the living and the fossil forms, and to realize the: 
prominent position occupied by this group in the Paleozoic period, 
a position in striking contrast to the part played by the diminutive. 
survivors in the vegetation of the present day” (p. 30). From the 
modern club-moss Lycopodium, the Selaginella, and the Jsoetes, all 
humble ground-plants, we pass to Arborescent Lycopodiales, Lepido- 
dendron and Sigillaria, often spoken of as ‘‘ Giant Club-mosses”’, and 
1 Vol. i appeared in 1898 (pp. vii, 452, with 111 illustrations, 12s.), and was. 
reviewed in the GrozoctcaL Magazine for May, 1898 (pp. 228-32) 
