288 



NATURE 



[January 25, 1894 



our author. A reference to Prof. Huxley's Anniversary 

 Address [Q. J. Geol. Soc. xxvi. [1870] p. 43) might be 

 usefully added to the note on p. 658. And when we pass 

 from theoretical questions to matters of actual fact, the 

 treatment of this branch of geology is no less difficult. 

 Mow often does it consist of little else but tables of names 

 of formations (comparative or otherwise), lists of fossils, 

 and other statistical information, that make it about as 

 lively as a parish register or a regimental roll-list. How 

 often do we ungratefully curse for its dismalness a book 

 of this kind, to which we are glad enough to turn for 

 reference. And at first it looks as if this could not be 

 helped, for if we are to give within reasonable compass 

 only a summary of what is known of the stratigraphy of 

 the world, what space is left for more than dreary 

 statistics ? Fortunately there are two matters directly 

 arising out of the bare facts of stratigraphy, which give 

 life to its dry bones ; the light which the rocks of a 

 region throw on its physical geography at the time they 

 were formed, and the connection between the fossils of 

 geological epochs and the general evolution of life on the 

 earth. For these space must be found, because without 

 these our narrative is no more geology than a list of dates 

 is history. These points have not been lost sight of in 

 the present text-book. 



The oldest rocks of the earth's crust are in the present 

 edition prudently grouped together under the head of 

 pre- Cambrian. Of the many names given to these rocks 

 all but this have involved more or less of unjustifiable as- 

 sumption ; but in this there is comparative safety, for what- 

 ever difference of opinion there may be about the upper 

 limit of the Cambrian, there is a fairly general provisional 

 agreement as to where its base is to be placed. The 

 account of the pre-Cambrian rocks has been recast and 

 amplified ; the term is not used as a "dumping ground 

 for everything of unknown age," but the claims of the 

 rock groups described under this head to the antiquity 

 which the name implies are canvassed. Additional de- 

 tails as to the recent work of the Geological Survey in 

 the North-west Highlands are introduced. Attention 

 is also called to the fact that portions of the Archaean 

 schists have in more than one locality been shown to be 

 intrusive, and that the amount of the Archaean has 

 thereby been materially reduced. But it must not be 

 overlooked in this connection that the pebbles in the 

 conglomerates of the Torridian and other pre-Cambrian 

 clastic rocks prove the existence of crystalline schists of 

 Archaean type before these beds were deposited, and so 

 leave a residue of Archaean rocks that no future dis- 

 coveries can abolish. Further additions in the present 

 edition deal with the rocks of the Central Highlands pro- 

 visionally classed as Dalradian, and the researches of 

 American geologists among their Fundamental Complex 

 and Algonkian. The amount of new matter in this part 

 of the book makes it practically a new work. 



Within the space of this article it will not be possible 

 to do more than glance at the many subsequent improve- 

 ments. The account of the Silurian Rocks of North 

 Wales is hardly up to date, and specially the treatment 

 of the May Hill Beds leaves somewhat to be desired. 

 The insertion of a table giving the results of Prof. Lap- 

 worth's work in the Southern Uplands of Scotland is a 

 recognition that all geologists will welcome. The De- 

 NO. 1265, VOL 49] 



vonian section is enriched by an account of the re- 

 searches of Mr. Usher and Prof. Kayser. Under the 

 head of the Carboniferous System the account of the 

 distribution of the fossils of the English coal measures 

 is hardly up to the mark. It is scarcely brought out 

 with sufficient distinctness that the marine shells are 

 found only in a few thin bands, and that these are by no 

 means confined to the Canister Beds. It is questionable, 

 too, whether it was worth devoting so much space to the 

 attempts of Grand'Eury and others to zone the carboni- 

 ferous rocks by means of their plants. There are those 

 among us who yet recollect Hooker's warning as to the 

 value of specific distinctions between fossil plants, which 

 has been since enforced by the discovery that two genera 

 so seemingly distinct as Lepidodendron and Halonia are 

 really difTerent parts of the same plant. A most im- 

 portant addition to the Permian section is an account of 

 the marine type of the Permian rocks, which, if I mistake 

 not, now finds for the first time a place in an English text- 

 book. Under the Jurassic section attention is called to 

 Neumayr's speculations as to the climatic belts of that 

 period. Among the Cretaceous deposits due notice is 

 taken of the work of Mr. Lamplugh and Prof. Pavlow on 

 the Specton Clay. The treatment of the Gault and Upper 

 Greensand is hardly satisfactory. The views as to the 

 relationship of these two groups, by no means new but 

 largely enforced by the work of Mr. Jukes-Browne, are 

 only indicated ; and the reader will hardly gather that, 

 as is stated so unhesitatingly in the last report of the 

 Director-General of the Geological Survey, the two groups 

 really constitute one formation. Have red-tape regula- 

 tions here forbidden the author to give to the public the 

 benefit of survey discoveries till they have been 

 announced in an official form ? This seems a pity, but 

 red-tape is hardly likely to see it in this light. In the 

 Gossau Beds we find a striking instance of the difficulty 

 of keeping a book up to date ; not many weeks have 

 passed since a paper was read before the Geological 

 Society, which will probably largely increase our know- 

 ledge of this somewhat exceptional formation. One 

 very useful addition among the Tertiary Rocks is a fuller 

 notice of Mr.Clement Reid's studies of the Cromer section. 

 The last book, on Physiographical Geology, is a little 

 disappointing. The author has made earth-sculpture 

 and other branches of this division of geology so specially 

 his own, that we could have wished for more under this- 

 head than the concise summary he has given. True^ 

 he would have been repeating what he has said often- 

 times before ; but his contributions to this most fascinat- 

 ing subject are rather scattered, and a full summary 

 would have been very welcome. 



The above notes, which are not the result of a system- 

 atic collation of this and the previous edition, but have 

 been culled at random, suffice to show that no pains 

 have been spared to bring before the reader the latest 

 results of geological inquiry. In a rapidly growing 

 science the task of keeping edition after edition of a 

 text-book up to date must be toilsome ; it is fortunate 

 when we have an author who has the courage to stick 

 to the work, and power to carry it out with success. It 

 is a welcome fact that this third edition, in spite of its 

 150 additional pages, is less bulky than the second. 



A. H. Green. 



