130 THE JOURNAL OP BOTANY 



consideration of the plants of the past is brought into close touch 

 with the study of their modern" descendants, and a much greater 

 interest is imparted to the book than it would have possessed had 

 it dealt entirely with fossils. 



The Lycopods are treated very fully. The anatomy of the typical 

 species, Lepidodenclron vasculare Binney, is described in detail, and 

 useful summaries of the anatomy of nine other species are given. 

 XJlodendroid and Halonial forms are discussed, and the principal 

 types of Lepidodendroid cones are described. The Bothrodendrece. 

 are given a separate chapter, while the results of much modern 

 work is incorporated in the chapters on Sigillaria and Stigmaria. 



The second half of the book deals with the Ferns. The intro- 

 ductory chapter on modern ferns is a most interesting piece of 

 work, particular attention being given in it to the orders of ferns 

 most closely related to some of the fossil types. In the sub- 

 sequent chapters the past history of the OsvumdacecB, Matoninea, 

 and other families is described and illustrated in a lucid manner. 



Several of the groups of Mesozoic Leptosporangiate forms are 

 nearly related to recent genera, but, as we go back to Carboni- 

 ferous times, forms with sporangia of the Marattiaceous type 

 appear to become dominant. Summaries are given of a number 

 of the genera which have been instituted for some of these types. 



A large number of the Palaeozoic ferns had, however, little 

 similarity to any of the modern forms, but exhibit many features 

 which may be regarded as primitive. A considerable amount is 

 known of the Botryopterea, and Zygojyterecs, and they have been 

 placed in a group to which various names have been given. Prof. 

 Seward points out that not one of these names is altogether satis- 

 factory, and proposes the new designation of Ccenopteridece, for this 

 group. He thinks that the name Primofilices, which Arber in- 

 troduced for them, implies that they were absolutely rather than 

 relatively primitive. 



The concluding chapter is on the various genera of fern-like 

 plants of uncertain affinities, probably either ferns or Pterido- 

 sperms. While this chapter may present little to interest the 

 general student of botany, it will be invaluable to those who wish 

 to study the floras of the past. It gives a short critical account 

 of those genera of fossil plants — such, for example, as Glossopteris 

 — which entered so largely into the composition of ancient floras. 

 These genera are founded almost entirely on- structureless leaf- 

 impressions, and are therefore often neglected by botanists, but we 

 urgently need more information about them. 



As in vol. i., we have at the end of the book a large biblio- 

 graphy of the works mentioned in the text. It contains about six 

 hundred references to articles from very numerous sources, and 

 cannot fail to be most useful to students and investigators. 



The book is profusely illustrated with several hundreds of 

 drawings and photographs. Most of them bring out very clearly 

 the points of interest, but we could wish that some of them had 

 not been reduced so much. There are few important subjects in 

 the text which are not amply illustrated by figures. 



