May 



■0, 



1911] 



NATURE 



413 



Outlines of Zoology. By Prof. J. Arthur Thomson. 

 Fifth edition, revised. Pp. xxii + 855. (Edinburgh, 

 Glasg-ow, and London : H. Frowde and Hodder 

 and Stoughton, 19 10.) Price 12s. 6d. net. 

 In the case of a book written by such an experi- 

 enced writer and teacher as Prof. Thomson, 

 and especially at the appearance of a fifth edition, 

 there is little room for critical comment. The quali- 

 ties that have made this work such a successful hand- 

 book are well known to generations of Scotch 

 students; the conciseness of its information, the 

 caution of its statements, and the clearness of its 

 comparisons. Even in its older form this text-book 

 was notable for its close texture, for the compact 

 nature of its information. Now that all the bearings 

 of modern work upon its topics have been incor- 

 porated, it is a rendering not only of the outlines of 

 zoology, but of much of the '"corpus" of zoological 

 knowledge, and he would indeed be a full man who 

 could really possess the store of information, both 

 old and new, that is contained in its pages. 



Almost the only general criticism we have to make 

 is the inadequacy of the treatment of the coelom- 

 theory. This important and difificult subject has re- 

 cently been exf>ounded so clearly in Prof. Sedgwick's 

 text-book of zoology, and is of such fundamental 

 importance that the fragmentary presentation in the 

 book before us is a matter of regret, affecting, a« 

 it naturally does, nearly every division of the animal 

 kingdom. The discussion on Echinoderm larvae on 

 p. 278 fails through such a want of what Moseley, 

 we believe, described as "morphological grip." The 

 "absence of the apical sense-organ" mentioned at 

 the bottom of that page is surely an oversicfht. The 

 apical plate is well developed in Echinid larvae, and 

 even bears eye-spots. 



The text has been most carefully revised. Very 

 few mistakes have been overlooked, but two call for 

 mention. One of the most recently discovered insects 

 — Acerentomon — is figured, a welcome sight, on 

 p. 362, and is described there as being without 

 antennae, though antennae are figured and described 

 in the legend. The other occurs on p. 235, where, in 

 the second paragraph, the word "sexes" is written 

 "series." .Such minute defects are, however, of little 

 account. A notable feature of this edition is the large 

 number of new figures. 



Etude sur I'Assurance cofnpi^mentaire de I'Assurance 

 sur la vie. Avec de twmbreux divcloppernents sur 

 les Assurances cotitre la Maladic ct I'Invaliditd. By 

 P. J. Richard. Pp. iv+ii8. (Paris: A. Hermann 

 et Fils, 191 1.) Price 3.50 francs. 

 Thf.rk has lately been a movement among insurance 

 companies in various parts of the world to combine 

 with ordinary life insurance benefits dependent upon 

 sickness, so that in the event of incapacity no pre- 

 miums are pavable, and sometimes an annuity is 

 received. This movement has led to the mathe- 

 matical investigation of the underlying principles, and 

 the .subject has proved attractive to one or two 

 writers, owing, perhaps, to its complexity, for it is 

 necessary to deal with the probabilities of death, sick- 

 ness (permanent and temporary), and recovery, all 

 of which vary with the age and occupation of the 

 life assured, as well as with the time that has elapsed 

 since the person was medically examined for insurance. 

 M. Richard, in his recent pul)lication, evolves the for- 

 mulae that mi^ht be used, and gives specimen tables 

 to enable us to form an idea of how the premiums 

 mirht be calculated, although, as he points out, we 

 have not sufficient '<tafistical data to enable us to use 

 his formulae satisfactorily. 



The best solution of the problem is probably the 



NO. 2169, VOL. 86] 



statistical one which sets out on one hand the pay- 

 ments made to the offices, and on the other the 

 various benefits allowed to the insured. The subject 

 is, however, at present too new on its practical side 

 to enable us to use this solution, and until experience 

 provides us with data, M. Richard's neatly-printed 

 little book will prove interesting to those who are 

 concerned with actuarial problems in theory and 

 practice, and have perhaps already been attracted to 

 the subject on which he writes by the earlier work 

 of Schaertlin and a few other writers. 



Recueil d'CEuvres de Leo Errera. Physiologic 

 gdnerale. Philosophic. Pp. xiv + 400. (Brussels: 

 H. Lamertin ; London : Williams and Norgate, 

 1910.) 

 The late Prof. Errera was possessed of an inherent 

 faculty for analysing subtle problems by a process 

 of concise, logical argument, and this faculty is par- 

 ticularly apparent in his treatment of certain of the 

 general physiological subjects discussed in this fourth 

 volume of collected papers. One of the best instances 

 is supplied by the notes arranged for a course of 

 lectures debating the existence of a vital force in 

 plants. Two lectures on sleep were delivered before 

 an audience composed largely of doctors. The view 

 put forward by the author that sleep is induced by 

 the formation of toxic bodies was opposed by several 

 doctors present, but was not refuted. 



Three papers only can be classed as direct con- 

 tributions to botany, although arguments are deduced 

 from the plant world in all of them. One of these 

 discusses the question whether acquired characters 

 can be inherited, and answers it in the affirmative 

 on the strength of cultural experiments with .\spcr- 

 gtllus niger, carried out by Dr. Hunger in the Botan- 

 ical Institute at Brussels. Another paper dealing with 

 the struggle for pre-eminence as exemplified by the 

 growth of lateral branches of a conifer when the 

 main stem is destroyed, was read before the British 

 Association at the Cambridge meeting in 1904. Two 

 essays on the individual and the assertion of life are 

 published for the first time. The papers generally 

 manifest a copious knowledge and ready application 

 of the latest scientific facts, and botanists in particular 

 A'ill appreciate the arguments and views expressed 

 with regard to spontaneous generation and the exist- 

 ence of a soul in plants. 



Wild Flowers as They Groiv. Photographed in 

 Colour direct from Nature. By H. Essenhigh 

 Corke, with descriptive text by G. Clarke Nuttall. 

 Pp. vii+197. (London: Cassell and Co., Ltd., 

 igii.) Price 5s. net. 



The first point of interest in this volume is supplied 

 by the coloured illustrations, which are the outcome 

 of photographs taken from nature direct by the 

 Lumiere process, and reproduced by a four-colour 

 printing operation. Most of the colour tones are well 

 rendered, notably the yellow and green of the prim- 

 rose, the blues of the harebell flower, and the blended 

 colours of the bee orchis ; only the yellow colours of 

 the dandelion and toadflax are distinctly incorrect. 

 From a combined natural and artistic point of view 

 the wild strawberry is excellent, as are several others, 

 especially when it is considered that an exjxisure of 

 minutes is required for taking the photographs. In the 

 accompanying letterpress Mr. Nutlall presents a clear 

 and precise description, adapted for general readers, 

 of the chief features of biological interest observable 

 in the twenty-five plants selected, and comments on 

 the popular names, superstitions, and other such de- 

 tails. The text and illustrations together form an 

 attractive volume, and the cost is moderate. 



