Bibliographical Notices. 465 



will prove indispensable, while to the student of sociology and to the 

 medical man it will probably come as a revelation, for it must be 

 admitted that neither of these last has shown that grasp of the 

 significance or the possibilities of heredity, certain exceptions 

 apart, which the circumstances of their professions demand. 



As a judicial summary of a peculiarly difficult subject Prof. 

 Thomson's book is masterly, while from the point of view of clear- 

 ness of exposition it has no rivals. 



In the space at our disposal an exhaustive account of the contents 

 of this book would be impossible. It must suffice, then, to point out 

 one or two of its more important features, and to make mention of 

 one or two small criticisms. 



Anything like criticism of a book of this kind seems ungrateful, 

 but the few comments we have to make are made in no captious 

 spirit. 



In the first place, then, we cannot help feeling that Prof. Thomson 

 endeavours to draw too nice a distinction between heredity and 

 inheritance. The former, he remarks, " is no entity, no force, no 

 principle, but a convenient term for the genetic relation between 

 successive generations'' while inheritance, he says, " includes all that 

 the organism is or has to start with in virtue of its hereditary rela- 

 tion." One cannot help feeling that this is putting " heredity " in a 

 straight-jacket. In other words, the term " inheritance " supplants 

 the more familiar " heredity," at any rate to all intents and 

 purposes. 



Our next grumble is at the omission of " opsonins " and their 

 relation to disease, which we naturally expected to find in the 

 otherwise most philosophical chapter on heredity and disease. The 

 only reference thereto is contained in a passage where, referring to 

 phagocytes and their relation to pathogenic microbes, he introduces 

 the subject in the phrase " or as his [man's] ' opsonic index ' 

 improved." 



The chapters on Mendelism are most admirable ; nowhere else 

 will there be found so complete and so illuminating a summary of 

 all that pertains to Mendelism. But while the author is generous 

 in his appreciation of this work, he is careful to utter a very 

 necessary word of caution as to the need of restraining enthusiasm 

 over the many triumphs which workers in this new field have 

 attained ; for he remarks, " In many ways . . . "Weissman's some- 

 what subtler and more complex conception of determinants which 

 work out a character by cooperative development appears to us to 

 fit the facts better." 



The chapter on the transmission of acquired characters leaves 

 nothing to be desired, and may be studied with the greatest profit 

 both by the medical man and the breeder ; and this because among 

 both there exists an appalling amount of misconception and, appa- 

 rently, wilful blindness to observed facts. The sociologists stand 

 in no less need of learning, and in the pages of this splendid treatise 



Ann. & Mag. N. Hist. Ser. 8. Vol. ii. 33 



