March 23, 1905] 



NA TURE 



48- 



.-iiuiquity of the South African land-mass ; and on the 

 su|)Lrficial formations (die Deckschichten). In chapter 

 XXXV., entitled " Die Mesozoische Wiisten-periode," 

 tin; author discusses the different stages of alteration 

 shown both by the older rocks and by the superficial 

 formations, through " einkieselung " or cementation 

 bv infiltrated silica, and " verkieselung " or replace- 

 ment of carbonates by silica ; and he gives his reasons 

 for recognising successive periods of alteration and 

 deposition consequent upon changes in the physical 

 ronditions of the land. He goes far afield in his 

 .■irgument, touching upon the various effects of rock- 

 weathering under almost every climate of the globe, 

 but with especial reference to desert-conditions. He 

 brings this information to bear upon the South African 

 g((jlogy generally, where he recognises evidence for 

 desert-conditions of great antiquity and long duration, 

 but with occasional intermission. Whether these 

 speculations are well founded it will remain for the 

 keen investigators now working in South Africa to 

 decide. 



In the same strain of more or less hypothetical de- 

 duction following upon an epitomised re-statement of 

 the main facts, are the next tvi-o chapters — xxvi. " Die 

 Pi riode der Brack wasserkaike und der Laterite," and 

 xxvii. " Die Pluvialzeit und ihr Abklingen bis zur 

 Gegenwart " — in which the probable condition of the 

 interior of South Africa is traced through Tertiary and 

 post-Tertiary times. It seems somewhat hazardous to 

 correlate the isolated and widely scattered patches of 

 thin sandstone and limestone by their lithological 

 characters alone, and to assign them to successive 

 periods. One line of argument by which the author 

 reaches his conclusions with respect to the age of 

 the desert-beds of the Kalahari is by comparing them 

 with the more readily determinable Tertiary succession 

 of Egypt. On questionable grounds he suggests that 

 his " Pfannensandstein " may be assigned to the 

 Kocene, his " Kalaharikalk " to a somewhat moist 

 episode in Miocene and Lower Pliocene times; after 

 which he recognises a period of dry conditions in the 

 Middle Pliocene, and then a Pluvial period of late 

 Pliocene and early post-Pliocene times. This Pluvial 

 period may be accepted with some confidence as being 

 in close relation to the occurrence of the Glacial period 

 in northern Europe. Evidence from many other parts 

 of the world tends to show that the progressive 

 desiccation that has gone on since that period has 

 not by any means been confined to the African 

 continent. 



Among the interesting side-issues raised or re- 

 capitulated in these later chapters of the book are 

 questions as to the antiquity of the Kalahari fauna ; 

 the geological effect of wind-action ; the obliteration 

 of dry river-beds; " zoogene erosion '"; the change of 

 climate in North Africa during historic times ; and 

 others that we have no space even to catalogue. 



The next — and last — chapter gives a review of the 

 plant-life of the Kalahari, with especial reference to 

 the evidence which it bears as to the changing con- 

 ditions of the land. Then follow various appendices, 

 occupying one hundred pages. These contain a few 

 astronomical observations ; a petrographical description 

 NO. 1847, VOL. 71] 



of 447 rock-specimens and slides by Prof. Kalkowsky ; 

 twelve chemical analyses of rocks ; an account of the 

 land and freshwater shells from the newer superficial 

 deposits by Prof. E. v. Martens; a full account of the 

 diatoms by H. Reichelt; and a list of plants. The last 

 twenty-seven pages of the book are occupied by the 

 classified indices. 



There is no attempt at artistic embellishment in the 

 text-illustrations ; and the same may be said of the 

 numerous sheets of maps, plans, and sections con- 

 tained in the " Karteiiband," some of which, indeed, 

 appear scarcely to justify their reproduction, while in 

 many the scale seems to be unnecessarily large. 



And now that we have growled our way through 

 the book, and have earned the concluding pipe of 

 peace, let us add that when a capable and earnest 

 worker is willing, in publishing his results, to under- 

 go the severe labour that a production of this kind 

 must have entailed, our sense of gratitude toward 

 him should be paramount, and should stifle all minor 

 complaints and especially the impatient grumbling 

 that arises in the main from our own unrealised 

 indolence. G. W. L. 



ANIMAL PHOTOGRAPHY. 

 Photography jor the Sportsman Naturalist. By 

 L. VV. Brownell. American Sportsman's Library. 

 Pp. xviii4-3ii; illustrated. (New York: The Mac- 

 millan Company; London: Macmillan and Co., 

 Ltd., 1904.) Price 8s. 6d. net. 



ON several previous occasions we have had the 

 pleasure of noticing some of the admirable 

 volumes belonging to that series of the " Sportsman's 

 Library " which deals exclusively with the various 

 animals constituting the sportsman's quarry. In the 

 volume now before us we have, on the other hand, 

 one of a second series devoted to different aspects 

 of sports and matters connected therewith. In re- 

 garding practical photography as an essential element 

 in the education and outfit of every modern sports- 

 man who desires to be something more than a mere 

 slayer of game, the editor has undoubtedly been well 

 advised ; and he also has been exceptionally fortunate 

 in securing the services of an expert with the ex- 

 perience and reputation of Mr. Brownell to make 

 known to the beginner the mysteries of the camera 

 and the technique of outdoor animal photography. 

 If the reader is careful to bear in mind that when 

 the author refers to " our animals " he means the 

 members of the North American and not of the 

 British fauna, the book will, we venture to think, 

 prove as acceptable to sportsmen and field-naturalists 

 on this side of the Atlantic as to the countrymen 

 of the author ; and if this turn out to be the case, a 

 wide circulation would seem to be assured. 



In his introduction Mr. Brownell gives a concise 

 and yet comprehensive sketch of the history of photo- 

 graphy, dwelling especially on the enormous strides 

 it has made during the last half-dozen years. The 

 loss of time that he himself experienced in having to 

 learn everything for himself when first taking up 

 animal photography is alluded to as a kind of justifi- 

 cation fif one be needed) for the appearance of his 



