348 Recently published Ornitholoyical Works. 



of problems which lie at the very root of the secrets of 

 evolution, we are not likely to get much further by still 

 more assiduous collecting. The time has tlierefore arrived 

 wlien it behoves us to make use of the vast mass of data 

 collected ; the time has come when the more comprehensive 

 student of zoology must take thought and marshal the facts 

 gleaned by himself and others in the hope of probing the 

 grand secrets of nature. 



As one more effort in this laudable direction we welcome 

 Mr, Bonhote^s volume, the object of which is to expound a 

 tlieory w'hich, while recognising the partial truths of Mendel's 

 and Galton's theories of inheritance and the part, within its 

 limits, played by Natural Selection, seeks to reinforce such 

 theories and to clear them up where they fail. 



Mr. Bonhote's medicine is a theory of Vigour, and by 

 vigour he means " activity of nutrition and function " or 

 " rate of metabolism." 



The first five chapters of the book are taken up in 

 the enunciation of the author's ideas on vigour and its 

 eifect on the coloration and sex of mammals and birds. 

 Then come five chapters devoted to experimental results, 

 while finally we have six chapters dealing with the 

 evolution of sex, the psychology of reproduction, and the 

 consideration of various hypotheses concerned in the in- 

 heritance of characters. Whether Mr. Bonhote attains the 

 object which he had in view in setting forth his theory we 

 prefer to leave to the judgment of those who read his book, 

 which we confidently recommend as affording much food for 

 thought in many interesting directions, whether we altogether 

 agree with his theory or not. 



The dominant idea which Mr. Bonhote puts forward is 

 somewhat heterodox and is comprised in the thesis that 

 environment, using the term in its wider sense, afl'ects the 

 physiological status of the parent and may have some 

 influence on the characters of the offspring, the vigour of 

 the parent being reflected in the vigour of the germinal 

 cells and hence in the vigour and character of the inherited 

 determinants. Mr. Bonhote, in fact, seems to partially, if 

 not actually, accept the fact of the inheritance of acquired 



