March 8, 1906] 



NA TURE 



437 



but in some cases, e.g. in Todea, we find lignification 

 almost identical with that of certain gymnosperms. 



On the whole the author may be congratulated on 

 having attained the end which he had in view, 

 namely, by tracing the history of a definite organ 

 through the vegetable kingdom, to demonstrate the 

 fruitfulness of the phylogenic method. F. D. 



OUR BOOK SHELF. 

 Economic Geology of llic United States. By Heinrich 



Ries. Pp. xxi + 435. (New York: The Macmillan 



Company; London: Macmillan and Co., Ltd., 



1905.) Price 2.60 dollars net. 

 This volume embodies the elementary course of 

 economic geology at Cornell University, where the 

 author is assistant professor. Some knowledge of 

 geology and mineralogy on the part of the student 

 is presupposed, and the work deals exclusively with 

 North American mineral deposits. At the same time 

 North America is so preeminently the continent of 

 mineral deposits, nearly all types and forms being 

 represented within its vast mineral areas, that a 

 treatise on American economic geology is nearly the 

 same thing as a study of mineral deposits in general. 



The mode of arrangement differs from that of other 

 books on the same subject in that predominance is 

 given to the non-metallic minerals, the value of the 

 production of which exceeded that of the metallic 

 minerals in 1903 by thirty million pounds. The 

 twenty chapters into which the book is divided deal 

 respectively with (1) coal; (2) petroleum, natural gas, 

 and other hydrocarbons ; (3) building stones ; (4) clay ; 

 (5) lime and calcareous cement ; (6) salts ; (7) gypsum ; 

 (8) fertilisers; (9) abrasives; (10) minor non-metallic 

 minerals; (11) mineral waters; (12) soils and road 

 materials; (13) ore deposits; (14) iron; (15) copper; 

 (16) lead and zinc; (17) gold and silver; (18) silver 

 lead; (19) aluminium, manganese, and mercury; and 

 (20) minor metals. 



In each chapter the treatment is the same. An 

 account of the minerals is followed by particulars of 

 their distribution in the United States, with sketch 

 maps, details of their use, recent statistics of their pro- 

 duction in the United States and in the world, and a 

 carefully selected bibliography. The twenty-five plates 

 reproducing photographic views of mines and the 

 ninety-seven diagrams in the text are alike excellent. 

 Altogether the work is an admirable one, and we 

 strongly commend it to teachers in this country as 

 a source of concise, accurate, and recent information 

 regarding the mineral deposits of the United States. 



Botanische Jahrbiicher. Edited by Dr. A. Engler. 

 Vols, xxxiii., xxxiv., and xxxv. Parts i.-iii., 

 with index vols. i. to xxx. (Leipzig : W. Engel- 

 mann, 1902-5.) 



The series of papers produced under the direction of 

 Dr. Engler, as the " Beitrage zur Flora von Afrika," 

 continues to engage the attention of workers at the 

 botanic museum in Berlin. The papers that give 

 merely descriptions of new species are chiefly service- 

 able to monographers, but the results become more 

 interesting when they are collated for a genus or an 

 order, as in the revision of the Ochnaceae by Dr. 

 Gilg. In a short article that will be found in 

 Beiblatt, No. 79, Dr. Engler summarises the general 

 progress of the study of African botany in Berlin, and 

 indicates where further collections and explorations 

 are required. He refers to Dr. Fulleborn's collections 

 of the lower algae and Bacillariales taken from Lake 

 NO. 1897, VOL. 73] 



Nyassa. They have been examined by Dr. Schmidle 

 and Dr. Otto Muller, and their descriptions and de- 

 ductions are published in these volumes. Other 

 systematic compilations include a contribution to the 

 flora of Madeira and the Canary Islands by Mr. J. 

 Bornmiiller, some notes by Drs. Gilg and Loesener 

 on the flora of Kiao-chau, the Chinese territory that 

 was occupied by Germany in 1S98, and the " Frag- 

 menta Phytographiae Australis occidentalis," written 

 by Drs. Diels and Pritzel. Among the cryptogamic 

 contributions, Mr. G. Hieronymus publishes an 

 account of the pteridophytes collected in Ecuador and 

 Colombia by Mr. H. C. Lehmann, German Consul, 

 and Mr. E. Lemmermann deals with the algal vegeta- 

 tion in the Sandwich Islands. Among the ecological 

 papers, Mr. J. Holmboe sketches the botany of the 

 Norwegian moors. Mention should also be made of 

 the notices in the Beibldtter of addresses delivered 

 before the Society of Systematic Botanists, of which 

 not the least interesting is that by Prof. K. Fritsch 

 discussing the systematic position of the monocoty- 

 ledons. 



The index to the first thirty volumes published in 

 1904 is an important reference book to systematic 

 botany from 1881 ; the systematic index, and the 

 catalogue under countries, will be found most useful. 



The Practical Photographer. Edited by the Rev. F. 

 Lambert. (Library Series.) No. 27, Photographic 

 Optics and Lenses, pp. xxiv+64. No. 28, The 

 Optical Lantern for Projection and Enlarging, 

 pp. xxiv + 64. (London : Hodder and Stoughton.) 

 Price, each vol., is. net. 

 These two volumes form the December and January 

 issues of this useful series of photographic handbooks. 

 As usual, each is prefaced by a short essay on the 

 pictorial work of some well known photographer 

 written by the editor, and in these cases we are made 

 acquainted with the photographic work of Mr. 

 W. A. I. Hensler and Mr. Charles H. L. Emanuel. 

 They are also accompanied by a series of reproduc- 

 tions from the best works of these photographers, 

 which illustrate, more than words can describe, the 

 particular styles of treatment. 



In the volume on photographic optics we have a 

 series of notes by numerous authors on various points 

 relating to lenses. These are more or less miscel- 

 laneous in their nature, but the several items are 

 generally clearly described, and may prove serviceable. 

 Numerous diagrams and process reproductions are 

 included in the text. 



The volume on the optical lantern contains many 

 useful wrinkles which will materially aid the beginner 

 and prove useful to those who are already acquainted 

 with the manipulation of a lantern. Forms of 

 lanterns, illuminants, condensers, reflectors, are all 

 fully treated, and in addition there is much miscel- 

 laneous information on lantern optics, and sundry 

 items pertaining to lantern work. Included in these 

 pages are process reproductions of several photo- 

 graphs, details about which are given under " Pic- 

 torial Notes." 



The Sanitation of a Country House. By Dr. Harvey 

 B. Bashore. Pp. vi4- 103. (New York : John Wiley 

 and Sons; London : Chapman and Hall, Ltd., 1905.) 

 This little book would form a useful, popular, and 

 non-technical guide on sanitary matters to anyone 

 about to build a country house, but is necessarily one 

 for America, and the practice recommended and de- 

 tails given would not always suit this country. The 

 illustrations and diagrams, sixteen in number, are 

 excellent. 



