DARWINISM'S PRESENT STANDING. 3^7 



possess in this state of affairs the much sought for, often 

 postulated, all-necessary, automatic modifying principle an- 

 tedating and preceding selection which must 



A determinate 



though not pur- effect change, determinate though not purpose- 

 poseful change, ful ? Nageli's automatic perfecting principle is 

 an impossibility to the thorough-going evolutionist seeking 

 for a causo-mechanical explanation of change. But an 

 automatic modifying principle which results in determinate 

 or purposive change, that is, in the change needed as the 

 indispensable basis for the upbuilding of the great fabric of 

 species diversity and descent ; is not that the very thing pro- 

 vided by the simple physical or mechanical impossibility of 

 perfect identity between process and environment in the case 

 of one individual and process and environment in the case 

 of any other ? It seems so to me. 



But I do not know. Nor in the present state of our knowl- 

 edge does any one know, nor will any one know until, as 

 Brooks 14 says of another problem, we find out. We are 

 ignorant; terribly, immensely ignorant. And our work is, 

 to learn. To observe, to experiment, to tabulate, to induce, 

 to deduce. Biology was never a clearer or more inviting 

 field for fascinating, joyful, hopeful work. To question life 

 by new methods, from new angles, on closer terms, under 

 more precise conditions of control ; this is the requirement 

 and the opportunity of the biologist of to-day. May his 

 generation hear some whisper from the Sphinx ! 



APPENDIX. 



1 One of the most serious and detailed critical analyses of the 

 selection theory, resulting in conclusions totally antagonistic to Dar- 

 Wigand's criti- winism, is that of the Marburg botanist, Prof. Albert 

 cismoftheselec- Wigand, composing the three volumes entitled "Der 

 tion theories. Darwinismus und die Naturforschung Newtons und 

 Cuviers" (Vol. I, 1874; Vol. II, 1876; Vol. Ill, 1877). From the 

 "Announcements" at the beginning of each volume I quote as 

 follows : 



