14 



The Journal of Heredity 



add greatly to the charm and interest 

 of the book. 



While he takes great pains to make 

 clear man's close kinship to all livins: 

 things and emphasizes the chemical and 

 physical laws that are the "physical 

 basis of life," the author does not 

 adopt the views of the extreme mechan- 

 istic school. In particular one state- 

 ment deserves consideration by those 

 who feel that the existence of a "phys- 

 ical basis of life" is sufficient to "ex- 

 plain" life : "The biologist starts with 

 life as it now exists, just as the phy- 

 sicist starts with energy and the chemist 

 with atoms on all their infinite complex- 

 ity. They do not try to explain energy 

 and oxygen and carbon." 



Nearly half of the book is given up 

 to discussion of heredity or related 

 matters. The final chapter. Biology 

 and Progress, deals with the application 

 of what man has learned about life and 

 heredity to every day afl^airs. Summar- 

 izing, the author says: "In this brief 

 sketching of some of the more prob- 

 able fields of progress which will give 

 a better understanding of man, no rev- 

 olutionary changes are anticipated, nor 

 is it suggested that fundamental laws 

 will be altered. Progress must rather 

 be in conformity with those principles 

 which clearly indicate that we must 

 recognize the ineradicable influence of 

 heredity and that the right of being well 

 born has a scientific foundation ; that 

 good food and a wholesome environ- 

 ment play an important part in well 

 being ; . . . and that mankind cannot 

 set aside these basal relations." 



Most of the author's views would re- 

 ceive the approval of students of hered- 



ity, but before leaving this excellent 

 book, attention should be called to one 

 or two statements that possibly are not 

 altogether clear. In explaining Mendel- 

 ian inheritance he says : "When the 

 peas of this (first) hybrid generation 

 are planted, the plants are partly tall 

 and partly short, but none are inter- 

 mediate. In the subsequent breeding 

 of this experiment the short peas give 

 rise to short peas and the tall ones to 

 tall peas," which is a result that would 

 hardly be expected by the scientific 

 breeder. 



Certain of his views on evolution 

 might also be questioned by many stu- 

 dents in this field. After remarking 

 that artificial breeding has produced no 

 new species, he adds : "This seems to 

 mean that the more than hundreds of 

 thousands of genera and species became 

 fixed before man had thought seriously 

 of questioning their origin. The result 

 is that the life of today is highly spe- 

 cialized and adapted to a given environ- 

 ment. This gives a non-plastic series 

 of forms to deal with, and science has 

 been thus far utterly unable to recon- 

 struct the conditions under which the 

 former changes took place." It is hard 

 to see why the present living forms 

 should he considered any less plastic 

 than their ancestors. Evolution is not 

 something that happened in the past, 

 but a vital, living force today. The 

 Origin of Species was published only 

 about half a century ago, and evolution 

 has been studied experimentally for 

 only the last twenty years. True, the 

 ]:)roblem is not yet solved, but that no 

 progress has been made, few students 

 of evolution would be willing to admit. 



