336 



SCIENCE 



[N. S. Vol. XXXVII. No. 



at the higher level in order to find something 

 subsequently to be reduced to, or explained by, 

 mechanistic principles if possible? But with 

 everything mechanistic in the sense only of 

 being consistent with mechanistic principles, 

 or of being caused, would there not still be 

 something left over which would not be iden- 

 tical with mechanism in the precise and tech- 

 nical sense of that term? It is the conviction 

 that there would be — a conviction which can 

 be based on proof — ^that has actuated the re- 

 viewer to write this rather long notice of Pro- 

 fessor Loeb's book. Everything that exists is 

 not identical with nor explainable by mech- 

 anism in the technical meaning of the term, 

 although it is compatible with it in the sense 

 that one fact can not contradict or exclude 

 the reality of another, and is in some relation 

 with it. And all science is not physics, chem- 

 istry and physical chemistry. The tendency 

 of many scientists to maintain the negative of 

 these two propositions is a misleading influ- 

 ence and a stimulus to false hopes, especially 

 when prominence in science lenA its weight 

 to the claim. But the tendency is not only a 

 dangerous one ; it also represents a bias which 

 is contrary to that broad-mindedness which is 

 held to mark the scientific mind. It is be- 

 cause Professor Loeb's book exemplifies this 

 tendency to so marked a degree, that the 

 opportunity of reviewing the book has been 

 used to enter protest. As a collection of 

 essays in the application of physical chemistry 

 to biology one can only praise the volume. 

 But as a philosophic work, which finds in this 

 application ground for insinuating the uni- 

 versal validity of the mechanistic conception 

 in some precise sense, but really making this 

 only most general, one can only doubt and 

 question. The scientist may justifiably resent 

 the intrusion of the philosopher into science's 

 realm, unless the philosopher becomes scien- 

 tist. But when the scientist becomes philos- 

 opher, as does Professor Loeb, he exposes him- 

 self to that broader scientific criticism which 

 is philosophy. The venture may be daring, 

 but does not the daring only seem? For are 

 not " we ourselves only chemical mechan- 

 isms " ? Then where lieth the blame if some 



atoms become philosophers and in the combat 

 some philosophers become atoms? 



E. G. Spaulding 

 Princeton University 



The Birds of Africa. By G. E. Shelley. 



Volume v., Part 2. Completed and edited 



by W. L. ScLATER. London: Henry Soth- 



eran & Co. 1912. Pp. viii-f 165-502; pis. 



L.-LVII. 



The publication of Captain G. E. Shelley's 

 elaborate work on the birds of Africa was in- 

 terrupted in 1906, after the appearance of the 

 first part of the fifth volume, by the serious ill- 

 ness and consequent death of the author. 

 Mv. W. L. Sclater, whose knowledge of the 

 African avifauna well fits him to carry out the 

 original plan, has undertaken to complete the 

 work; and the present instalment is the first 

 to appear under his supervision. 



The general treatment of the subject is the 

 same as in previous volumes. Brief diagnoses 

 of superfamily groups, or " sections," are 

 given; also keys to families and subfamilies; 

 with diagnoses of families and keys to genera. 

 Each genus is defined, furnished with proper 

 synonymy, a key to its species, and in most 

 eases with a statement of its geographical 

 range. Under specific headings are given per- 

 tinent synonymy; descriptions of the adult 

 plumage of both sexes, and, where possible, of 

 Juvenal and nestling; brief measurements, 

 apparently of single birds; a general state- 

 ment of geographical distribution, and a good 

 account of habits, often '•■wo or three pages 

 long, and including mention of many par- 

 ticular localities where the bird has been ob- 

 served. 



Little account is taken of subspecies, when 

 recognized as such, and none are given sepa- 

 rate headings. They are treated, if at all, in 

 the text under their respective species, with 

 sometimes a binomial, sometimes a trinomial 

 name. Some are, however, considered as ab- 

 solute synonyms; while a few are given full 

 specific rank. Of those recognized as sub- 

 species the synonymy is given, and usually, 

 though not always, the diagnostic characters. 



The book includes nominally 209 species 



