242 



NATURE 



[August 24, 191 1 



the precise equivalents of the Dorsetshire Kimeridge 

 and Portland beds; he is disposed to adopt the 

 view that the division between Kimeridgian and 

 Portlandian should be drawn through the middle of 

 the Kimeridge clay. The brief reference to the 

 English rocks leaves more space for the account of 

 their Continental representatives, of which a summary 

 of recent work is of most value to British geologists. 

 The classification of the Cretaceous system adopted 

 by Prof. Haug shows that there is no prospect of 

 agreement as to the nomenclature. He subdivides 

 this system into three groups, the Eocretaceous, all 

 of which he regards as Neocomian ; the Meso- 

 cretaceous, for the period of the great Cretaceous 

 transgression during the Albian, Cenomanian, and 

 Turonian ; and the Neocretaceous, for the upper divi- 

 sions, all of which he calls Senonian. 



Prof. Haug, on the authority of Prof. Cayeux, 

 accepts (p. 1 161) the depth of the chalk sea as not 

 more than 150 fathoms. Mr. Jukes-Browne, on the 

 other hand, has recently reasserted the view that 

 parts of the chalk are truly deep-sea deposits. M. 

 Cayeux's low estimate is inadmissible for some 2ones 

 of the English chalk. 



One of the most instructive features of this treatise 

 is its indications as to the progress of opinion on the 

 principles and problems of stratigraphy, which are 

 especially well illustrated by the Mesozoic rocks. 

 Prof. Haug decides in favour of the existence in 

 Jurassic times of well-defined climatic zones. The 

 influence of climate on the distribution of the Jurassic 

 fauna was recognised by Marcou in i860, and Neu- 

 mayr in 1883 defined five climatic zones approximately 

 parallel to those of the present day. Several authori- 

 ties have, however, denied their existence, and Prof. 

 Haug shows that some of the arguments upon which 

 Neumayr based his zones, can no longer be main- 

 tained. It would have been very surprising if thirtv 

 years' further palaeontological research had not modi- 

 fied the known range of some of the fossils. Thus the 

 genera Phylloceras and Lytoceras are less character- 

 istic of the equatorial zone than Neumayr thought, 

 and the distribution of those genera proves to be con- 

 trolled rather by depth than by climate. There has 

 also been a greater interchange between the faunas of 

 the boreal zone and the north temperate zone in 

 western Europe than was known to Neumayr. 

 Nevertheless, Prof. Haug concludes that the existing 

 evidence confirms the existence of the Jurassic 

 climatic zones, though he retains onlv the boreal 

 and equatorial zones of Neumayr. The fuller 

 evidence now available enables him to recognise in 

 Upper Jurassic times several well-defined zoological 

 provinces. 



The nature of earth movements is a problem of 

 which Prof. Haug's solution greatly affects his views. 

 He adopts a law that subsidence in one locality is 

 compensated by simultaneous elevation in another. 

 Hence transgressions of the sea upon the land are not 

 universal, for while the sea is advancing in some 

 places it is retreating elsewhere. This law is in 

 direct conflict with the principles of Prof. Suess, and 

 though there is no general discussion of the question 

 in the present volume, attention is prominently 

 NO. 2182, VOL. 87] 



directed to various instances where the evidence is 

 consistent with Prof. Haug's law. Prof. Haug has 

 prepared a series of maps of the distribution of land 

 and water at various geological dates ; their most 

 novel and useful feature is the importance attached 

 to the bathymetric conditions under which the beds 

 were deposited. They, however, show an extreme 

 acceptance of the view so characteristic of much 

 French geology that beds were laid down in existing 

 geosynclinals, and their occurrence in long, nar- 

 row bands is due to original distribution and 

 not subsequent denudation. The maps of the 

 world constructed on this principle do not look 

 convincing. Thus Prof. Haug's map of the Jurassic 

 world (p. 1113) represents by far the larger part as 

 land with the seas in the Lower Jurassic limited, 

 excepl in Europe, to narrow bands. Hence, according 

 to Prof. Haug, instead of the oceans having been 

 permanent throughout geologic time, there were 

 periods with no oceans at all. The same map, more- 

 over, considerably exaggerates the area in western 

 Australia submerged by the middle Jurassic trans- 

 gressions. Where the ocean waters were stored dur- 

 ing the dry intervals is not explained, and the evidence 

 available as to the Jurassic climates renders any such 

 vast excess of land most improbable. Prof. Haug is 

 to be congratulated on the value of this work, of 

 which perhaps the chief drawback is the omission of 

 economic geology. J. W. G. 



PiJ.-lC77C.4L DIETETICS. 

 Food and Feeding in Health and Disease: a Manual 

 of Practical Dietetics. By Dr. C. Watson. Pp. 

 xvi + 638. (Edinburgh and London : Oliver and 

 Boyd, ro.10.) Price 10s. 6d. net. 



THE subject of food and diets has rightly attracted 

 considerable attention of late. When dealing 

 with a community of individuals — soldiers and sailors, 

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 by a local authority, it is obvious that a knowledge of 

 the food values, nutritive and calorific, of the articles 

 of diet, may conduce to considerable economy. On 

 the other hand, a mere knowledge of the chemical 

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 Thus gelatin is nearly related to protein in elemen- 

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In disease and convalescence it is essential for the 

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In the present work the whole subject of food and 

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