334 



NATURE 



[September i6, 1909 



The papers on general botany collected in the two 

 volumes noted above are of a popular nature, as his 

 more technical contributions have been published in 

 the Recueil de I'lnstitut boianiqite de I'Universiti 

 de Bruxelles. The first is a letter describing the 

 vegetation in the neighbourhood of Nice, written 

 when he was sixteen years old. The article on the 

 structure and methods of fertilisation of flowers 

 appeared four years later; it was inspired by Charles 

 Darwin's work, and the introductory quotation from 

 the "Origin of Species," taken in conjunction with 

 his essay on Darwinism, is worth reproducing : — 

 " Whoever is led to believe that species are mutable 

 will do good service by conscientiously expressing his 

 convictions." The article is, to a large extent, an 

 account of contemporary investigation, but includes 

 original notes on the oxlip and the genus Pentstemon. 

 The essay entitled " L'ne Le<;on eltinentaire sur le 

 Darwinisme " was revised in 1903, after the publica- 

 tion of de Vries's book. Errera fully accepts the 

 mutation theory, regarding it as an amplification, and 

 not a contradiction, of the selection theory. The 

 references in this paper to Dr. Scott's work on 

 Cheirostrobus and the joint communication by Drs. 

 Scott and Oliver on Lagenostoma will serve to indi- 

 cate how the author incorporated the very latest re- 

 sults into his teaching. 



The most interesting part of the third volume, con- 

 taining miscellaneous verse and prose, will be found in 

 the collection of extracts and aphorisms. Here is an 

 epigram that will be appreciated by philosophers 

 generally : — " La v^rite est sur une courbe dont notre 

 Esprit suit eternellement I'asymptote." The authors 

 of the biography are to be congratulated on present- 

 ing such an interesting account of the brilliant 

 alumnus of Brussels University. The papers are 

 worthy of consultation, not alone for the facts con- 

 tained, but also for style and arrangement. 



OUR BOOK SHE^F, 

 An Atlas of Skiagrams, iUnsirating the Development 



of the Teeth, witli Explanatory Text. By Dr. J. 



Symington, F.R.S., and Dr. J. C. Rankin. 



Pp. 47 ; pi. xii. (London : Longmans, Green and 



Co., 1908.) Price 10s. 6d. net. 

 The difficulty of cutting sections comprising both soft 

 and highly calcified parts without causing displace- 

 ments, and the further trouble of piecing together the 

 disposition of parts in a large number of serial sec- 

 tions so as to reconstruct a model in the solid, gives 

 to skiagrams an especial value, as being a representa- 

 tion of the relations of the developing teeth to one 

 another and to the jaws which is beyond suspicion 

 of disturbance. Certain difficulties arising from the 

 teeth being disposed in an arch were very successfully 

 met by the authors, who resorted to tipping the back 

 of the skull upwards to a uniform extent in all cases, 

 namely, raising the back about 30 degrees, and by 

 this method the shadows of the front teeth were 

 separately projected and the overlapping of the 

 shadows to a great extent avoided. The skulls used 

 were divided into halves, and the right and left sides 

 both presented in nearly every case where the skulls 

 used were more than seven years of age ; but in the 

 younger ones, no difference being found between the 

 two sides, only one is presented. 



The ages of the subjects used range from birth to 

 adult life, and twenty-three skiagrams are given which 

 NO. 2081, VOL. 81] 



illustrate the calcification of the temporary teeth and 

 their change to the successional set ; amongst other 

 points clearly shown, the extent of calcification in each 

 tooth, at each age, a point sometimes of medicolegal 

 importance, is well seen. Some points in the relation 

 of the growth of the jaws to the development of the 

 teeth can be advantageously studied in these skia- 

 grams, as well as the relation of the developing teeth 

 to the antrum. Inasmuch, however, as the walls oF 

 the antrum cannot always be very clearly traced in 

 the midst of shadows cast by other parts of the upper 

 jaws, the anatomy of the antrum is also illustratecf 

 by drawings made subsequently from the same 

 specimens, the technique adopted being to harden the 

 tissues in formol, and then to chip away as much of 

 the bone as could be removed without destroying all 

 support. The lining membrane so treated becomes 

 sufficiently firm to stand alone and retain its shape, 

 and the dissections made were carefully drawn. These 

 figures include also the accessory sinuses. The 

 authors may be congratulated upon having produced 

 an atlas which is of the greatest service in adding to> 

 the accuracy of our knowledge of the development of 

 the teeth and of their relations to the parts about 

 them. 



Mineralogie und Geologic fiir schweioerische Mittel- 



schulen. By Dr. Hans Frey. Dritte .Xuflage. Pp. 



iv+234. (Vienna: F. Tempsky ; Leipzig: G. Frey- 



tag, 1909.) Price 2.75 marks. 

 This W'ork, which has evidently been successful, is. 

 of the type commonly used in German-speaking 

 schools, and makes no special appeal to the beginner's- 

 interest in field-observation, or to the splendid object- 

 lessons ranged around him in his native land of 

 Switzerland. .\ number of Swiss illustrations are, 

 however, inserted, and the passages on mountain- 

 building and the Alpine lakes embody considerations 

 raised in recent times. To a British mind the 

 mineralogical section will seem to contain far too» 

 much in a small compass, if the course is to be gone 

 through systematically before the pupil enters on his 

 coHegialo years. It occupies half the book, and is 

 followed by a petrographic chapter, which similarly 

 bears traces of having been brought somewhat 

 hesitatingly towards modern modes of statement and 

 classification. 



The section on historical geology, perhaps in accord- 

 ance with a settled syllabus, is limited to thirty-four 

 pages, and the illustrations of fossils are given with- 

 out any explanation as to the nature of the organisms. 

 In these circumstances, the generic and specific names 

 are worse than useless ; they need, moreover, some 

 revision and press correction. A great opportunity 

 still remains for making the mineralogy and geology 

 of Switzerland serve as an introduction to these 

 sciences, and for letting the land itself speak to the 

 pupil, before he becomes entangled in the strings of 

 facts which are supposed to be inseparable from a 

 scientific education. G. A. J. C. 



Gilbert White and Sclhorne. By Henrj' C. Shelley. 



Illustrated from photographs by the author. Pp. 



xvi + 226. (London : T. U'erner Laurie, 1909.) 



Price 6s. net. 

 Tins little book is nut badly done so far as it goes, but 

 there is nothing in it that has not often been said 

 before; the photographs are good, but of quite familiar 

 objects. The one innovation consists in eking out a 

 volume offered at six shillings by " Cameos from the 

 Natural History of Selborne," which occupy fifty of 

 these meagre pages : a serious literary blunder, to 

 use a mild word. The six shillings might be much 

 better spent in the purchase of an edition of the famous 

 book, which is much talked of but probably little 

 read. 



