ZOOLOGY AND BOTANY, MICROSCOPY, ETC 121 



The design of tlie book is sufficieutly showa by the opening paragraphs 

 of the author's preface. 



" This book is intended for those who, without desiring to become 

 botanists by profession, wish nevertheless to become acquainted with the 

 elements of scientific structural botany. It will likewise introduce the 

 beginner to the various methods of microscopical manipulation. 



The study of vegetable structure is especially favourable as an initiation 

 into the use of the Microscope ; and any one whose future career will require 

 command over this instrument should commence with the study under the 

 Microscope of vegetable anatomy. 



The manual is divided into thirty-two chapters, each of which is in- 

 tended to provide materials for several hours' practical work in the 

 laboratory. The earlier chapters are easy, and the difficulties to be en- 

 countered increase almost continually up to the last chapter. The first 

 chapter assumes on the part of the worker entire ignorance as to the use of 

 his instruments, but nevertheless assumes the possession of some general 

 botanical knowledge. With this elementary preparation the beginner 

 ought to be able, by the diligent use of this book alone, to acquire a 

 tolerably broad knowledge both of vegetable structure and of the methods 

 of microscopical work." 



In our notice of the original work we characterized it as " extremely 

 useful " ; experience has proved that this was but faint praise. In its 

 improved English form it will take an even higher place as a leading hand- 

 book for microscopical manipulation. 



B. CRYPTOGAMIA. 



Cryptogamia Vascularia. 



Fertile Shoots of Equisetum.* — According to Herr K. Goebel the 

 fertile shoots of all those species of Equisetum in which these shoots differ 

 in structure from the barren shoots, result from the transformation of the 

 latter, both in a phylogenetic and in an ontogenetic sense, due to an arrest 

 of development. The difference consists essentially in the absence of 

 chlorophyll, the suppression of branching, the temporary duration of the 

 stem, and the absence of stomata ; as well as in the greater development 

 of the sheaths, which is difficult to explain from a biological point of view. 

 This view is confirmed by the fact that it is possible artificially to induce 

 the fertile shoots of E. arvense to put out green branches from the lower 

 internodes, chlorophyll being also formed in the main axis. This may 

 occur even in nature, producing the forms known as E. irriguum and 

 ripaiium. There is therefore no sharp line of demarcation to be drawn 

 between the two sections of the genus known as " homophyadic " and 

 " heterophyadic." 



Ulodendron and Bothrodendron. f — M. E. Zeiller agrees with Kidston 

 in arranging the fossil structures hitherto classed under Ulodendron in 

 three groups, and in referring the first to Lepidodendron, and the second 

 to the genera Ulodendron and Tthytidodendron, the latter including the 

 Bothrodendron of Lindley and Hutton ; but he does not accept Kidston's 

 view that the structures classed under Ulodendron belong to the section 

 Claihraria of Sigillaria. They are distinguished from these by the leaf- 

 scars being contiguous and arranged in oblique series. 



* Ber. Deutsch. Bot. Gesell, iv. (1886) pi3. 184-9. 



t Bull. Soc. Geol. France, xiv, (1886) pp. 168-82 (2 pis.). See Bull. Soc. Bot. France, 

 1886, Rev. Bibl., p. 108. 



