260 



Although not addressed to the author's colleagues (p. v) it will 

 surely (and ought to) receive a share of their attention, and parts 

 of it will call forth the protests of some of them, and the antagon- 

 ism of others. For example, Darwinian adaptation is advocated 

 (p. vi and throughout the text), and the corresponding language 

 of purpose is used — "Experiential purpose, which does not pre- 

 suppose any forethought." We are told (p. 334) that plants 

 really do "reach up after light"; that the need of light for stems 

 and the injuriousness of light to the unprotected protoplasm of 

 roots is the "reason" (p. 227) for their characteristic photo- 

 tropism ; that parthenogenetic reproduction has been adopted by 

 certain Compositae because it would be "natural" for them 

 "to preserve their characteristics unchanged by resorting to 

 asexual propagation." 



.But these forms of expression are perfectly logical for one who 

 believes (p. 326) that it is "scientifically correct as well as prac- 

 tically convenient, to personify nature." From this the reviewer 

 must emphatically dissent. He believes that nothing has been 

 more potent in retarding the development and advancement of 

 experimental inquiry in the past than the willingness to accept 

 final causes with satisfaction as really explaining the phenomena 

 of nature. This tendency is still strong, and to combat it at 

 every point is one of the duties and opportunities of the writers 

 of "popular" science. 



The author is a vitalist in that he assumes "the existence in 

 Nature of an X-entity, additional to matter and energy but of 

 the same cosmic rank as they" (p. viii). The "most reasonable 

 explanation of the phenomena of organic nature" is held to be 

 "that all of the life processes are subordinate to some influence 

 which is using living matter as a seat for its operations." All 

 protoplasm thinks (p. 14). The reviewer is here an agnostic, 

 but he believes that to ascertain the truth on this point is the most 

 fundamental and important problem, indeed the ultimate goal 

 of all biology. The mechanistic conception of life is fraught 

 with too serious a meaning for human beings to be accepted 

 without a challenge at every possible point and place. It is well, 

 therefore, to have a vitalistic point of view clearly set forth, and 



