36 



NATURE 



[November io, 1910 



THE COMPLETE BOTANY-TEACHER. 



The Teaching Botanist. A Manual of Information 

 iipon Botanical Instruction, including Outlines and 

 Directions for a Synthetic General Course. By 

 Prof, W. F. Ganong. Second edition, revised. Pp. 

 xi + 439. (New York: The Macmillan Company; 

 London : Macmillan and Co., Ltd., 1910.) Price 

 $5. net. 



1"^HE first edition of Prof. Ganong's book received 

 a welcome on this side the Atlantic such as is 

 accorded to few elementary botanical works produced 

 in America, and it has proved of the greatest value 

 to many engaged in the teaching of elementary botany, 

 or in training as future teachers of the subject. The 

 second edition, lately published, has been thoroughly 

 revised, and, indeed, re-written almost throughout, 

 besides being considerably enlarged, though the 

 general plan, and, above all, the animating spirit of 

 the book, not to mention the very moderate price, 

 remain unchanged. To all intents and purposes this 

 edition is a new work, and should be in the hands of 

 all botanical teachers, both in esse and in posse, 

 whether or not they already possess the first edition. 



In part i., occupying, roughly, half of the book, 

 the author deals in a practical, yet philosophic and 

 stimulating, manner with the place of the sciences in 

 education and of botany among the sciences, followed 

 by a thoughtful and vigorous discussion of the per- 

 tinent question, "What botany is most worth?" and 

 proceeds to the consideration of the training of the 

 good botanical teacher, the methods of good botanical 

 teaching, botanical drawings and descriptions, the 

 equipment of laboratories, and the arrangement of 

 collections. A valuable chapter follows on botanical 

 books and their use, with a bibliography — by no means 

 exclusively American — which, with a few deletions, 

 would serve as the catalogue of an ideal library for 

 any institution in which the subject is taught. One 

 is inclined to wonder when there will be found an 

 author^and publisher — courageous enough to publish 

 a 'black list" of undesirable books on botany and 

 nature-study generally; but, after all, this would 

 merely postpone for a time the oblivion into which 

 bad books are bound to sink sooner or later. 



As is well known. Prof. Ganong has shown him- 

 self, especially in his valuable "Plant Physiology," 

 to be an acute critic of many erroneous facts and 

 ideas, and of faulty methods of experimentation, which 

 are only too common in botanical literature, not only 

 in books of the baser sort, but even in standard and 

 authoritative works. In the present work he ends 

 part i. with a breezy and delightful chapter — only too 

 short — on some common errors prejudicial to good 

 botanical teaching, which will bring some discomfort 

 to conscientious teachers, while pointing out to them 

 the better way. Such teachers will, however, be to 

 some extent consoled by the author's candid confes- 

 sion that he, too, has occasionally perpetuated, and 

 even originated, ideas and phrases which are " unfor- 

 tunate if not erroneous." This chapter is certainly 

 deserving of most careful study by all teaching 

 botanists. 



NO. 2 141, vol. 85] 



In part ii. Prof. Ganong outlines a general course 

 in elementary botany — not a mere skeleton or series 

 of headings, but a thoroughly practical, fairly de- 

 tailed, and altogether excellent syllabus of instructions 

 for the carrying out of a very full year's work in the 

 morphology and physiology of plants. It would be 

 difficult to devise a better guide to the elements of 

 botany for those who may go no farther with the 

 subject, or a more suitable first-year course for those 

 who intend to proceed to more advanced work in 

 botany. This admirable and wisely designed course 

 of instruction may be warmly commended, not only 

 to teachers of botany, but to those who are responsible 

 for the drafting of examination syllabuses in the sub- 

 ject in this country. F. C. 



CLIMATIC CONDITIONS AND ORGANIC 

 EVOLUTION. 

 Die klitnatischen Verhdltnisse der geologischen 

 Vorzeit voni Praecambrium an bis zur Jetztzeit tind 

 ihr Einfluss auf die Entjvickelung der Haupttypen 

 des Tier- und Pflanzenreiches. By Dr. Emil 

 Carthaus. Pp. v + 256. (Berlin: R. Friedlander 

 und Sohn, 19 10.) Price 8 marks. 



I^'HIS treatise commences with a consideration of 

 the views of different authors upon the early 

 evolution of the earth. Of the rocks in the earth's 

 crust, Olivine rock (Dunite) is considered by the author 

 to be the most primitive, its formation having taken 

 place before the condensation of the water-vapour 

 contained in the very earliest atmosphere. The 

 gneisses, however, were formed after such condensa- 

 tion had occurred. The beginnings of organic life 

 were present in the original atmosphere of water- 

 vapour, but the author doubts the view of Arrhenius 

 that the early spores could have reached the earth 

 from other heavenly bodies. The period between the 

 Upper Cambrian and Purbeckian was one of little rain, 

 the existence of salt deposits in the early formations 

 at various places, widely separated from one another, 

 and the complete absence of real freshwater calcareous 

 deposits prior to the Jurassic being cited as evidence 

 in support of that view. In this connection the inter- 

 esting questions are propounded : Why have no re- 

 mains older than the fauna of late Tertiary or 

 diluvial times been found in the caves of Devonian, 

 Carboniferous, Triassic, and Jurassic limestones? 

 Whv did cave formation thus probably begin first in 

 Tertiary times? 



The occurrence of forests of Rhizophora (Dicotyle- 

 dons) in the sea of the Malay Archipelago is instanced 

 as a reason against the assumption of the necessarily 

 freshwater origin of the Ferns, Sigillaria, Lepido- 

 dendron, Equisetites, Conifers, and Cycads of- the 

 older geological formations. Great stress is laid upon 

 the difference in the movements of the sea-water as 

 affecting the forms of life at different times. The 

 increase of these movements in later geological periods 

 tended to destroy the brachiopods, the bilateral sym- 

 metry of the Tetracoralla gave v^ay to the radial 

 symmetry of the Hexacoralla, while the later Echi- 

 noidea, as compared with the earlier, underwent 



