1894. SOME NEW BOOKS. 377 



groups Thallophyta, Bryophyta, and Pteridophyta. We notice at 

 once a departure from the plan of the edition of Prantl, where the 

 chapters on physiology followed, we think more naturally, those 

 dealing with anatomy and histology. 



Speaking of physiology we are reminded of the author's text- book 

 on the subject, with which in one respect his more recent effort 

 compares unfavourably. We mean in mode of expression. The 

 " Physiology" was pleasant and comparatively easy reading, but the 

 students' text-book is stiff, and bristles with technical terms, many of 

 which will be new and strange even to the student who left off text- 

 books less than seven years ago. This is most noticeable in the 

 anatomical part. Thus, the plant unit is an energid, which becomes a 

 cell only when invested with a cell-v/all. An aggregate of energids, 

 e.g., the body of a Vaucheria, is a coenocyte, and coenocytic structure is 

 thus contrasted with cellular ; but we have also to distinguish the 

 multinucleate cell, which from being uninucleate has become multi- 

 nucleate by direct nuclear division, from the syncyte, a structure 

 developed from already-formed cells by a more or less complete 

 absorption of the separating walls, such as occurs in the development 

 of vessels. The employment of the term stele for the tissues derived 

 from the plerome entails a number of derivatives such as polystely, 

 schizostely, gamostelic, meristele, etc., which will make the botanist to 

 whom we have referred feel quite ancient. 



We like the part on morphology best, and note especially the able 

 way in which the more highly and more lowly organised plants are 

 considered from one broad point of view. The extension of root and 

 fruit into cellular plants, and a more general use of some other terms 

 helps to break down the exclusive barrier which has too severely 

 separated the larger groups. In treating of the leaf, the author 

 adopts Bower's view of differentiation along a longitudinal axis, or 

 phyUopodium, into hypo-, mesa-, and epi -■podium., the first forming the 

 leaf-base, including the sheath, stipules, and pulvinus, the second 

 the stalk, while the third is generally winged, forming the blade. 

 When we consider the extremely close relation between the parts, 

 and the frequent impossibility of accurate distinction, as well as the 

 continuity of structure, these divisions seem somewhat arbitrary. 

 A very admirable chapter is that on the cell, which forms a 

 splendid introduction to the anatomical section. We notice, however, 

 a slip on p. 112, where it is stated that "the proteid grain always 

 contains a mass of mineral matter,'' a statement disproved by some 

 work done in Dr. Vines' own laboratory at Cambridge. 



The most noticeable features in the portion dealing with classifica- 

 tion are the separation of Isoetes from Salviniaceae as a distinct order 

 of Heterosporous Eusporangiate Filicinae, and the well illustrated 

 account of the embryogeny of the lycopods. 



We sincerely hope that the " Students' Text-Book," by the pro- 

 duction of which Dr. Vines has increased the obligation the botanical 

 world already owes him, will not long remain incomplete. 



British Glaciation. 



Papers and Notes on the Glacial Geology of Great Britain and Ireland. 



By the late Henry Carvill Lewis, M.A , F.G.S. Edited from his unpublished 



MSS., with an introduction, by Henry W. Crosskey. Pp. Ixxxi. and 469. 



82 figures and lo maps. London : Longmans, 1894. Price 21s. 



Among all the vexed questions in British geology none has been the 



subject of more divergent theories, faddy speculations, and prolific 



