Jtme 6, [88 9] 



NATURE 



12 



age of the different Lower Palnsozoic rocks appears to be 

 of a fairly satisfactory character. 



Lying in the district between the two areas of older 

 rocks, we have, in the central parts of the island, a tract 

 of great extent, which is occupied by the important coal- 

 bearing strata. These strata have, however, been greatly 

 invaded by igneous extrusions, and are, over a consider- 

 able area, covered up by Tertiary deposits. While the 

 lower series of these coal-bearing strata contain the 

 rerhains of plants, like those of the Carboniferous strata of 

 Europe and the United States, the higher Coal-measures 

 yield many plants having Mesozoic affinities. 



Mr. Johnston, like all who have had to deal with the 

 geology of countries in the East and in the southern 

 hemisphere, has been compelled to confront a very serious 

 difficulty — that of making his nomenclature and classifi- 

 cation fit in with the scheme that has been adopted in 

 the countries which happen to have been the first 

 systematically studied by geologists. His biological 

 training and knowledge have here, however, stood him in 

 good stead ; and there are few contributions to this diffi- 

 cult question more worthy of attentive consideration than 

 the chapter of this work which deals with nomenclature 

 and classification, and the suggestions offered by the 

 author on the subject of the " distribution of genera in 

 time, from independent or widely separated geographical 

 centres." 



Mr. Johnston divides his Tertiary strata into the two 

 groups called by him Pal^EDgene (including perhaps the 

 Eocene, Oiigocene, and Miocene of European geologists) 

 and Njogene (corresponding'] with our Pliocene). It is 

 perhaps unfortunate that in the latter case a name 

 is employed which has also been'used by the geologists 

 of Eastern Europe with a somewhat different signification. 



Coming down to post-Tertiary ^times, the author gives 

 an excellent accoLint of the] caverns and native shell- 

 mounds, containing the"] rude flint-implements of the 

 aboriginal inhabitants. Portraits are given of the last 

 surviving man and woman of the Tasmanian race (King 

 Billy and Truganini), the former of whom died in 1869 

 and the latter as recently as 1876. Drawings of the rude 

 instruments made of chertj which were used by this 

 interesting race of human beings, and details concerning 

 the mode in which the natives employed the different kinds 

 ■of weapons, will prove of great service to those engaged 

 in studying the remains left by various ancient races in 

 Europe and America. 



Full justice is done to the different kinds of igneous 

 Tocks, so far as they have yet been studied ; to the various 

 economical products ; and^specially to the useful ores, 

 of the island. Interesting details are given concerning 

 the mode of occurrence of the " Tasmanite," or " white- 

 coal," which attracted so much attention a few years ago, 

 and first led to the investigation of many similar " spore- 

 coals " in Europe and America, The character of the 

 deposits from which stream-tin and gold have been 

 obtained is also described, and their importance is in- 

 dicated by accurate statistics : the value of the tin 

 obtained in Tasmania is now shown to be between 

 ^300,000 and 400,000 per annum. Nor are more purely 

 scientific and theoretical questions neglected. An inter- 

 esting discussion of the probable distribution of land and 

 ■water in the Australasian region before and during the 



Tertiary period is illustrated by sketch-maps ; and here, 

 too, the author's biological knowledge has aided him 

 greatly in dealing with a very complex and difficult 

 problem. 



Butquiteindependentlyof the scientific value of the work, 

 which as we have seen is certainly very great, we think 

 the Government and people of Tasmania are to be con- 

 gratulated upon .the character of this remarkable and 

 handsome volume. It aims at being above all things of 

 practical use, and its great object is to direct the attention 

 of the colonists to questions of pressing interest and im- 

 portance, as well as to secure their aid and co-operation in 

 solving the important problems presented by the geology 

 of the country. 



The bibliography of Tasmanian geology has, with the 

 assistance of Mr. Robert Etheridge, Jun , been very amply 

 dealt with. Chapters containing a key to the determina- 

 tion of rocks, and instructions for the blowpipe examina- 

 tion of minerals, together with a.n excellent glossary of 

 geological terms, which might seem out of place in a 

 memoir on European geology, will make this work of 

 service to many colonists who have not had the advant- 

 age of a scientific training or access to libraries. The 

 numerous plates, too, if not so highly finished in some 

 instances as we are accustomed to in works of the kind, 

 serve their purpose admirably ; and the plan of giving 

 side by side with the imperfect fossils found in the colony 

 a number of well-marked types from the other Australian 

 colonies, and even from Europe, can scarcely fail to prove 

 of the greatest service to many a traveller or resident in 

 the country, whose only work of reference may be this 

 volume. 



In the execution of his task, which has evidently been a 

 labour of love, the author has received much assistance 

 from the geologists in other Australian colonies and in New 

 Zealand, and this he warmly acknowledges. No less 

 valuable has been the co-operation of many of his fellow- 

 colonists, who have aided him by drawing plates, in 

 making special inquiries, and in many other ways. 



When invited to undertake the work, the author \yas 

 requested to prepare a volume which should be " specially 

 suited for the guidance of local students, mining pro- 

 spectors, and others." We can heartily congratulate Mr. 

 Johnston, and the Government which have so liberally 

 paid for the publishing of the book, upon having not only 

 completely accomplished their primary object, but of 

 having at the same time issued a work which is of the 

 highest scientific value. It is not often that the wants of 

 the general public and of the scientific specialist have 

 been so admirably met; or that a book has been produced, 

 which is at the same time accurate and thorough in its 

 treatment of technical questions, while it is not wanting 

 in the more elementary details required by those who 

 have not had the advantages of a scientific training. 



John W. Judd. 



CACTUS CULTURE FOR AMATEURS. 

 Cactus Culture for Atnateurs. By W. Watson. Profusely 

 Illustrated. (London : L. Upcott Gill, 1889.) 



QUAINTNESS of form, extraordinary brilHancy of 

 colour in the flowers, facility of cultivation, all 

 supply reasons why these plants, independently of the 



