7S 



NATURE 



lSeptember i6, 1920 



the text in the descriptions of the plates, which 

 are of material assistance. In short, the third 

 edition exhibits throughout the same careful atten- 

 tion to detail as its predecessors, and the work 

 fully maintains its position as the most valuable 

 handbook to the practical use of the microscope 

 as an optical instrument. 



Oil-Finding: An Introduction to the Geological 

 Study of Petroleum. By K. H. Cunningham 

 Craig. Second edition. Pp. xi + 324 + xiii 

 plates. (London : Edward Arnold, 1920.) Price 

 i6s. net. 



The second edition of this work has been enlarged 

 to nearly double the bulk of the first, the scheme 

 remaining the same, and there is little to add to 

 the review which appeared in Nature of Augusts, 

 1912, except to say that the revision of the work 

 has distinctly improved its quality. The author 

 is still insistent on the importance of the theory 

 of the origin of petroleum, and for him that of 

 vegetable origin and subsequent concentration, 

 controlled by geological structure, is supreme. 

 The treatment of this subject, regarded as of vital 

 importance, is inadequate, in so far that less than 

 six pages are devoted to theories of inorganic 

 origin, and thirty-four to a polemical examination 

 of the hypotheses of animal or vegetable origin; 

 yet there are many facts in the known distribution 

 of petroleum more easily explicable on the suppo- 

 sition of inorganic than on that of organic origin. 

 At present there are grave difiiculties in the way 

 of regarding either as even approximately com- 

 plete, and there is this to be said for the theory 

 and principles of application advocated by the 

 author, that they will lead to correct conclusions 

 in about nine cases out of ten, and in the tenth 

 success will depend mainly on luck, instinct, or 

 intuition. The chapters on field-work are very 

 distinctly improved, the approximate and im- 

 perfect methods indicated being relegated to their 

 proper place, as expedients which may have to be 

 resorted to by force of circumstances, and not, as 

 inexperienced readers of the first edition might 

 easily be led to believe, preferable to more exact 

 and thorough methods. 



Keys to the Orders of Insects. By Frank Balfour- 

 Browne. Pp. vii-fs8. (Cambridge: At the 

 University Press, 1920.) Price 75. 6d. net. 



Mr. Balfour-Browne has placed students 

 under an obligation by publishing this useful 

 series of tables, founded on notes drawn 

 up for those who have ' the advantage of 

 attending his courses of entomology at Gam- 

 bridge. The twenty orders of insects recognised 

 are first distinguished by means of a " key,'/ and 

 then the families of those six orders that may be 

 regarded as of greatest economic importance — the 

 Orthoptera, Rhynchota, Lepidoptera, Coleoptera, 

 Diptera, and Hymenoptera — are further discrim- 

 inated. The characters given are those of adults 

 only ; but in later editions the author proposes 

 to deal with some of the larval forms. It is to be 



NO. 2655, VOL. 106] 



hoped that these tables will serve to familiarise the 

 rising generation of entomologists with the Com- 

 stock system of nomenclature for wing nervuration, 

 and to hasten its use — perhaps with the modifica- 

 tions rendered necessary by Dr. Tillyard's recent 

 researches — among special students of all orders of 

 insects. Some points of detail in the tables need 

 correction. It is implied that all Thysanura have 

 the jaws retracted within the head ; this is not the 

 case with the two most conspicuous families, 

 Machilidaj and Lepismidas. Palps are not present 

 in the Anoplura and Rhynchota; probably "ab- 

 sent" was meant, but "present" has been 

 printed. In a new edition it would be well, if 

 possible, to break up the unnatural grou|j " Poly- 

 morpha " among the beetles, and it is to be hoped 

 that the sale of the book may enable the publishers 

 to reduce the price, which must be considered 

 high, although blank interleaved pages have been 

 considerately provided for students' notes. 



G. H. C. 



Catalogue of the Lepidoptera Phalaenae in the 

 British Museuvi. Supplement. Vol. ii. : Cata- 

 logue of the Lithosiadae [Arctianae) and Phalae- 

 noididae in the Collection of the British 

 Museum. By Sir George F. Hampson. 

 Plates xlii-lxxi. (London : British Museum 

 (Natural History), 1920.) Price 32s. 6d. 

 The present volume is supplementary to 

 vol. iii. of the great Catalogue of Lepidoptera 

 Phalaenae. Owing to the European War it has 

 remained in manuscript since 191 5, but has been 

 brought up to date so far as possible. It includes 

 no references to German publications which have 

 appeared since August, 1914, for the reason just 

 mentioned. Two families of Lepidoptera are 

 dealt with — the LithosiadjE (Arctianse) and the 

 Phalienoididae. Of the former, vol. iii. included 

 147 genera and 845 species, and to these are 

 added in the present work twenty-five genera and 

 no fewer than 12 15 species. Of the second family 

 (Agaristidae of manv authors), the original num- 

 bers are increased by seven genera and eighty 

 species. In his selection of family and generic 

 names Sir George Hampson has adopted views on 

 nomenclature which have been largely rejected by 

 most svstematists, but he has wisely adhered to 

 the system utilised in the already issued volumes. 

 We need only add that the book is well printed 

 and up to the standard of the previous parts of 

 the catalogue. 



Historical Geography of Britain and the British 

 Empire. (In two books.) Book 1. The 

 Making of England; The Making of Empire; 

 The Establishment of Empire: B.C. 55 to a.d. 

 1815. By T. Franklin. Pp. viii + 216. (Edin- 

 burgh : \\'. and A. K. Johnston, Ltd. ; London : 

 Macmillan and Co., Ltd., n.d.) Price 25. net. 

 Book I. is divided into three sections; the first 

 deals with the growth of England from the time 

 of the Roman invasion to the beginning of the 

 sixteenth century, the second with the building-up 

 of the British Empire during the two succeeding 



