482 



NATURE 



ju^E b, 1911 



with t,'rcat respect, lie has witnessed many storms 

 and startling phenomena in all parts of the world, 

 and has sought to ascertain the causes according to 

 his lights. Not being sufficiently acquainted with 

 |)hcnomena outside his own experience, and perhaps 

 misled by the " long arm of coincidence," he has gone 

 wrong, but the spirit of inquiry exhibited is very 

 creditable, and much to be preferred to tlie display of 

 indifference so often manifested by seamen and others. 



D'xc Cnidosporidicn (Myxosporidieu, Aclinomyxidien, 

 Microsporidien). Eine nionographischc Studie. By 

 Dr. M. .'\uerbach. Pp. viii + 261. (Leipzig: Ver- 

 lag von Dr. Werner Klinkhardt, 1910.) Price 18 

 marks. 



This memoir deals with an important group of para- 

 sitic Protozoa, associated with disease in cold-blooded 

 vertebrates, especially fishes, and in invertebrates, for 

 instance, pdbrine in silkworms. The spores of these 

 Sporozoa are enclosed in a valvate shell (the valves 

 of which are shown to arise from two or three special 

 cells in the sporoblast), which contains, besides one 

 or more masses of spore-plasm, one to four polar 

 capsules, each with a spirally-wound filament. The 

 assertions of some workers that the polar filaments 

 can be extruded and subsequently retracted are not 

 borne out by the author's experience. The morphology 

 of the vegetative forms and spores and the multiplica- 

 tive and propagative reproduction are fully described ; 

 some form of sexual reproduction is novv known to 

 occur in members of each of the three subdivisions 

 of the Cnidosporidia. 



In the biological portion of the work the occur- 

 rence of the parasites is discussed, and an excellent 

 host-index is given showing the Cnidosporidia re- 

 corded from each, with references to the records; the 

 situation of the parasite and its pathological effects 

 are described. In the systematic section an account 

 is given of the genera and species described subse- 

 quent to 1897, which thus serves as a supplement to 

 Labb^'s account in "Das Tierreich " (1899). There 

 are useful hints on technique, a list of 530 memoirs 

 dealing with this group of parasites up to August, 

 iqo9, and an appendix giving a summary of the 

 literature issued between that date and the time of 

 printing. .'\ comprehensive index completes this 

 admirably arranged and useful monograph, which is 

 illustrated with eighty-three half-tone figures. 



Lehrbiich dcr Botaiiik fiir hohere Lehraustaltcn und 

 die Hand des Lehrers, sowie fiir alle Freunde der 

 Natiir. By Prof. O. Schmeil. (Sechsundzwan- 

 zigste Auflage.) Pp. xvi + 534. (Leipzig: Quelle 

 and Meyer, 19 10.) Price 5.40 marks. 

 The author of a book that passes through twenty- 

 five editions in seven years has reason to be satisfied. 

 Such .is .the record of Dr. Schmeil's "Text-lxiok of 

 Botaiiv.,". .^which. is. intended for use in high schools 

 and similar institutions, as well as for teachers and 

 home students. It is largely a systematic compila- 

 tion treating of phanerogams, with a shorter review 

 of cryptogamic types; to this is added an account of 

 general morphology and physiology, and a brief 

 appendix on plant systems and geographical distri- 

 bution. The success of the book may be attributed 

 to the training value of systematic botany in a general 

 course of education. The information proceeds by 

 families, for which one or more of the important 

 members is taken for tolerablv full description, 

 especially with regard to features of biological in- 

 terest, while others, particularly those of economic 

 interest, are mentioned, and in'manv cases figured. 

 Among the numerous illustrations those portraying j 

 NO. 2 171, VOL. 86] 



general habit and appearance are a notable feature 

 .Most of the coloured plates refer to an individu.d 

 species, but one is a representation of a wood in the 

 carboniferous epoch. It would be useful if general 

 characters were given for each family mentioned; us 

 It is, they are omitted in those cases where fhf>y are 

 not readily obtainable. 



Four-l'ifiiirc Logarithms on a A i a- iirapnn .svi/rm, 

 dispensing with Interpolations. By Dr. R. C. 

 Farmer and M. M. Farmer. Pp. 6. (London : 

 Longmans and Co., 1910.) Price 6d. net. 



The authors of these tables have attempted to avoid 

 the necessity of employing difference columns. With 

 this end in view, numbers are printed on one side 

 of a graduated line, drawn down the page, and the 

 corresponding logarithms are placed opposite to them. 

 The difference between successive printed numbers is 

 i») and the intermediate spaces are divided into ten 

 parts. The logarithms are alio printed at intervals 

 of ten, and the correct subdivisions are indicated. It 

 is claimed that more accurate readings will be made 

 in this way than from the ordinary tables where a 

 slight error in the fourth place occasionally occurs. 

 But we must confess that we have found this new- 

 method a considerable strain on the eyesight, and 

 there is the additional inconvenience of having three 

 pages to consult instead of one. For practical pur- 

 poses, ordinary tables give a sufficient degree of 

 accuracy ; we therefore doubt whether this new- 

 graphic system, in itself distinctly ingenious, will 

 receive much support. 



Die Abstammungslehrc. By Dr. P. G. L>ucjvt:i>. 

 Pp. xi + 354. (l.eipzig : Quelle and Meyer, 1909.) 

 Price 4.40 marks. 



This is a very good little book. It presents the main 

 facts bearing on the theory of descent, which have 

 been ascertained of recent years, within a convenient 

 compass. The account of variability is ven,- useful, 

 but what will probably be found of greatest use ti» 

 German readers will be the author's epitome of the 

 mutation theory and his account of elementary specie> 

 in Draba and Viola, of which there are some very 

 useful figures. His chapter on tlie natural system of 

 classification is very interestingly written ; he deals at 

 length and is evidently very much interested in the 

 question of the minute discrimination rendered pos- 

 sible by a long training of the observation, and he 

 mentions a bulb dealer who knows more than a 

 thousand varieties of hyacinths from the dry bulbs 

 alone. His concluding chapter embodies an attempt 

 to hold the scales between the mutation theory- and 

 the theory of the selection of continuous variations. 

 The author makes an unequivocal declaration in favour 

 of the theory of mutation ; his thoughtful analysis of 

 the evidence on this question should ensure the book 

 a wide circulation. It is to be hoped that it may be 

 translated into English. 



The Cornish Riviera. Described bv Sidnev Heath. 

 Pp. 64. The Peak District. Described by R. M. 

 Gilchrist. Pp. 64. Dickens Land. Described by 

 J. A. Nicklin. Pp. 64. All pictured by Ernest 

 Haslehust. (London: Blackie and Son, Ltd., 1911.) 

 Price 2s. net. 



These additions to the " Beautiful England " series 

 which Messrs. Blackie are publishing contain all the 

 attractive features to which attention has been directed 

 in noticing previous volumes. Mr. Haslehust's beau- 

 tiful pictures in colour, supplemented as they are by 

 bright, entertaining letterpress, should assure the 

 popularity of the volumes. 



