Revietvs—Dr. D. H. Scott — Studies in Fossil Botany. 567 



America, the cyclone would have been driven in the direction of 

 Europe, causing mild weather in the latter, as in the case just given. 

 Such a view aifords a simpler explanation of the geological facts 

 than those usually adopted. Instead of supposing that the climatic 

 changes of the Great Ice Age, several times recurrent at intervals of 

 a few thousand years only, were due to astronomical causes, it is 

 here suggested that the climate of the Pleistocene epoch being 

 uniformly colder than that of our own era, conditions of comparative 

 warmth or cold may have been local, as they now are, affecting the 

 great continental areas at diiferent periods. 



I^ IB "^ I IE] -VT" S. 



I. — Studies in Fossil Botany. By Dukinfield Henry Scott, 

 M.A., Ph.D., F.R.S., F.G.S., Honorary Keeper of the Jodrell 

 Laboratory, Eoyal Gardens, Kew. pp. xiii, 553, with 151 

 illustrations. (London : A. & C. Black, 1900.) 



AS the title of Dr. Scott's work implies, " Studies in Fossil 

 Botany " is not a ' textbook ' in the ordinary acceptation of the 

 term, giving a systematic course of the entire range of fossil plants, 

 but contains thirteen lectures devoted to the microscopical structure, 

 morphology, and affinities of Carboniferous plants, and one on the 

 Mesozoic Gymnosperms. The groups studied are not chosen at 

 random, but follow each other in natural sequence. 



Lectures i-iii are devoted to the Equisetales. The Calamites are 

 first described, and here, as in the subsequent groups, a description 

 of the external characters of the group is given. These descriptions, 

 however, take a subordinate place to the description of the internal 

 organization of the plants, which forms the main subject of the 

 lectures. The development of the young Calamite is traced through 

 its early stages, and the different structures which go to make up 

 the complete plant are described in detail. One of the important 

 results of Dr. Scott's examination of the Calamites is to prove 

 that the carinal canals of Eqidsetum and Calamites are homologous, 

 both resulting from the rupture of the primary wood. After the 

 description of Arthropitijs, the common English form of Calamite, 

 the two other types of Calamite stem structure, Arthrodendron and 

 Calumodendron, are considered. The Calamite fructifications, Calamo- 

 stachys, Palceostachya, and Cingularia, are then dealt with and their 

 morphology discussed ; then follow notes on Arcliceocalamites and 

 Macrostachya. 



In Lecture iv the Sphenophyllales are considered. In this group 

 are placed the two genera Sphenophyllum and Cheirostrobus. This 

 is a specially interesting chapter, dealing with types of plant 

 structure which disappeared with Carboniferous times. Fortunately, 

 the structure of stems, roots, leaves, and fructification of Spheno- 

 phyllum is known. The two British species showing structure — 

 S. phirifoliatum, from the Lower Coal-measures, and S. insigne, from 

 the Calciferous Sandstone series — are fully described. Sphenophyllum 



