38o 



NATURE 



{Mar. 14, 1872 



a monograph with figures,by M. Bourguingnat, of all themol- 

 lusca of this age found in the Seine Basin. This well-known 

 conchologist makes out that out of a total of 76 there 

 are 38 new species which he considers as extinct, a con- 

 clusion which we expect English conchologists will hardly 

 be prepared to agree with, as they have detected no extinct 

 species in these deposits, and find only a few which are 

 not local — a view in which we also believe most French 

 conchologists join. The author considers that the same 

 mammalian fauna is common to both the high-level and the 

 low-level gravels. In one main point, however, do these 

 gravels differ. In those of the high-levels of Montreuil and 

 Bicetre no Human remiins, no Flint Implements, have 

 been found, whereas, in those of the low-levels of Clichy, 

 Crenelle, <S;c., above 5,000 flints, more or less worked, are 

 stated to have been found by a single collector. Besides 

 these works of early Man, M. Belgrand states that human 

 bones, skulh, and entire skeletons, have been found in 

 these lower gravels ; but it seems to us that much of this 

 evidence requires confirmation. 



The Quaternary period of the Seine Basin is coeval, in 

 M- Belgrand's opinion, with the Glacial period, and he 

 considers that it was brought suddenly to a close with the 

 low- level gravels. To this Ouaternary period the peat 

 deposits immediately succeed, owing, as the author in- 

 geniously suggests, to the suddenly diminished rainfall 

 leaving the rivers clearer and under conditions favourable 

 for the growth of peat, which he shows never takes place 

 in river valleys subject to frequent and heavy floods, but 

 always in valleys where springs abound, and the floods 

 are few and not turbulent. 



The latter part of the work is occupied with a minute 

 account of formation of gravel beds, and of the position 

 of the Organic Remains, showing ho at all the features of 

 those deposits are to be accounted for by ordinary river 

 action, and that the mammalian remains are abundant 

 precisely at those very places where a river with strong 

 currents and numerous eddies would leave them. He 

 endeavours to account alsjfor the fact of all the bones of 

 the larger animals being found in the coarser bottom 

 beds of gravel, by the circumstance that these coarser 

 beds were formed in those deeper water-channels along 

 which only the larger carcases could have floated, and 

 which were afterwards surmounted by those uppjr 

 beds of sand and finer gravel, which he considers 

 to be due to silting up {alluvionncment) of the chan- 

 nel where the river had changed its course to another 

 channel. The brick earth or Loess is ascribed by 

 him, as by English geologists, to river floods. But 

 instead of considering it, as we do, to be produced by 

 successive floods at all the various levels of the river, 

 from the high to the low level, M. Belgrand admits but 

 two levels, the high and the low, and that Ovving to a sudden 

 elevation of the land, the excavation between these two 

 levels was produced at once without intermediate stages. 

 Consequently, he considers that the height of the Loess 

 above these two levels marks in each case the rise of 

 the flood waters. This, we think, is a weak point in his 

 argument. According to his view, which he illustrates by 

 a section, showing the range of the Loess up the hill 

 slopes, he concludes that the floods of the lo^r-level 

 stage of the river rose, notwithstanding the width of 

 the valley, to a height of 66ft., and during the high- 



level stage, to a height of 43ft., which give very much 

 larger sectional areas for th^ river in flood than is other- 

 wise necessary, and such as we conceive the area drained 

 would have been insufficient to fill even with greatly larger 

 rainfa'l. For, although the discharge of the Arman- 

 con may in a particular cas; of heavy rainfall have been 

 so large as when multiplied by the whole area to give two- 

 thirds of the required supply, still it is perfectly well 

 known that the discharge by the main river never equals 

 the sum of all its tributaries, and the discharge of the 

 Seine at ■ Paris on that occasion actually only rose to 

 1,250 cubic metres per second. There are besides beds 

 of gravel on the slopes of Clichy towards Paris, and again 

 on the slopes leading to Charenton distinct beds of gravel 

 at intermediate levels, though of limited extent. 



Thus, IVI. Belgrand ascribes the gravel beds and the 

 Loess of th a Seine Basin to old river action, referring the red 

 loam alone of the higher plains above to diluvial causes, 

 in opposition to the view usually received in France, accord- 

 ing to which all these Drift beds are divided into the 

 three diluvial deposits of Z?///^w«/«^/7>, Diluvium rouge, 

 and Liinon or Loess. As we have already expressed 

 very similar views respecting the commonly accepted clas- 

 sifieation, we cordially agree with the author on this point. 



The illustrations forming the second volume constitute 

 a very interesting e.'chibicion of the art of Photo-litho- 

 graphy. The execution varies a good deal, and there are 

 plates which, though valuable for their truthfulness, are 

 rather indistinct. Some of the representations of the Flint 

 Implements are excellent. The work is somewhat large 

 and costly ; but as a copious record of facts, an ingenious 

 s':atement of theory, and a reliable representation of 

 specimens, this work of M. Belgrand will be greatly valued 

 by all those who feel an interest in the remarkable phe- 

 nomena connected with the present configuration of the 

 country, the distribution of life during the Ouaternary 

 period, and especially with the evidence bearing on the 

 Antiquity of Man. J. P. 



OUR BOOK SHELF 



The Discovery of a New World of Being. By George 



Thomson. (Longmans, Green and Co., 1871.) 

 The world discovered by this psychological Columbu; 

 is the '-world of spirits," although he "disclaims all 

 connection with so-called Spiritualists— a sect of modern 

 times," whom he somewhat ungenerously " believes to be 

 either dupes or knaves." Mr. Thomson believes that 

 man consists of two " personalities," an animal per- 

 sonality or body, and a personality he calls spirit, which 

 is the " knowing and conscious we," and which he believes 

 to be as distinct from and as capable of being at almost 

 any moment abstracted from the former as steam is from 

 a steam-engine. Indeed, this latter phenomenon takes 

 place every time the body "goes to sleep," to use the 

 vulgar phrase ; for Mr. Thomson believes that the 

 "animal life never sleeps, and cannot sleep, and that to 

 say or think that it, or any other life, can sleep, in the 

 popular sense of the word, is the most glaring absurdity 

 that ever has had possession of the human mind." " What 

 IS meant properly by sleep," he goes on to say, " is simply 

 the abstraction or withdrawal of the influence of a bemg, 

 a spirit, from a being, an animal, the leaving of a servant 

 to itself, from the influence of its lord and master." Mr. 

 Thomson explains the phenomenon of dreaming to be 

 the struggles of this " being, a spirit," to get out of and back 

 into the house of its servant, the body. The frequently 



