June 15, 1900. J 



SCIENGE. 



949 



valuable class and laboratory instruction as he 

 reports its use for five years with success. 



J. E. G. 



The Living Organism. An Introduction to the 



Problems of Biology. By Alfred Earl. 



London, Macmillan & Co. 1898. Pp. xiii 



+ 271. 



This book gives the too wordy reflections 

 upon biological phenomena of an author who 

 seems to have a fair general acquaintance with 

 biological principles, but no very extensive 

 knowledge of biological facts. The consequence 

 is a book which is philosophical in form, dis- 

 cusses biological phenomena in an extremely 

 general and abstract way, contains few errors, 

 but, on the other hand, has little of suggestive- 

 ness for the advanced biologist. The style is 

 flowing, but often obscure ; and after reading a 

 few pages one wearies of the pedantry which 

 clothes well-known and simple ideas in a heavy 

 blanket of abstract verbiage. Thus, the fact 

 that organisms assimilate is put (in Italics) thus : 

 "Both animals and plants depend for their 

 continued existence upon certain material which 

 is absorbed and changed in properties by con- 

 tact with the living body." This is typical (p. 

 227): "The remarkable constancy of the liv- 

 ing form, one of its distinctive signs, even when 

 united in thought with the ceaseless occurrences 

 tending to disturb that form, gives no positive 

 indication of other than physical agents. In- 

 deed, it is only by a just apprehension of every- 

 thing that concerns or affects the organism, in 

 other words, by a due regard to external 

 changes as well to the more prominent activity 

 of the organism, that it is possible to gain co- 

 herent knowledge of the fact known as life." 

 We must conclude that the book contains little 

 of importance for the working biologist. 



C. B. Davenport. 



suter's hand-book of optics for students 

 OF ophthalmology. 

 This little book, as its title implies, contains 

 such small portions of geometrical optics as 

 may be useful directly to a certain limited class 

 of students. Like all fragmentary text-books, 

 it suffers under the difficulties of such special 

 treatment. Many important portions of the 

 subject are omitted or barely mentioned, and 



only those are developed in detail which apper- 

 tain directly to the object in view. Thus the 

 introductory and general portions, including 

 the general treatment of refraction, are con- 

 densed almost to obscurity, and, considered as 

 demonstration, are incomplete. Refraction 

 through spherical surfaces is much more satis- 

 factorily handled, and is succeeded by an ex- 

 cellent chapter on lenses, following in general 

 the methods of Gauss. In both these chapters 

 the use of algebraic signs is somewhat arbitrary 

 and inconsistent. The principles thus ex- 

 pounded are then applied to the eye as an op- 

 tical instrument, both in its normal condition, 

 and in connection with the spectacle lenses 

 used to correct its errors of refraction. These 

 chapters form, as was to be expected, the most 

 important part of the book. They are clear 

 and instructive, and well illustrated by numer- 

 ical examples. They are followed by discus- 

 sion of cylindrical lenses, and prismatic glasses. 

 The final chapters on the ophthalmoscope are 

 too brief to be of great practical benefit. 



The whole presentation of the subject is ade- 

 quate to its immediate purpose, though the 

 rare student of ophthalmology who has enough 

 interest in the optical side of his work really to 

 profit by this book would find it much more to 

 his advantage to read instead a larger and 

 more complete treatise. 



Frank P. Whitman. 



books received. 



Memoirs Presented to the Cambridge Philosophical So- 

 ciety ore the Occasion of the Jubilee of Sir Gkokge 

 Gabriel Stokes, Bart, Hon, LL.D., Hons. SoD. 

 Lucasian Professor. Cambridge, at the University 

 Press ; New York, The Macmillan Company. 1900. 

 Pp. xxviii -\- 447 and twenty -five plates. §6.50. 



Papers ore Mechanical and Physical Subjects. OSBOEN 

 Eeynolds, F.R.S. Cambridge, The University 

 Press ; New York, The Macmillan Company. 1900. 

 Vol. I, pp. XV + 416. ?5.00. 



An Introduction to the Study of the Comparative Anat- 

 omy of Animals. Gilbert C. Bourne. London, 

 George Bell & Sons ; New York, The Macmillan 

 Company. 1900. Vol. I, pp. xvi + 269. $1.10. 



Zoological Besults, based on material from New 

 Britain, New Guinea, Loyalty and elsewhere, col- 

 lected during the years 1895, 1896 and 1897. 

 Arthur Willey. Cambridge University Press ; 



