r!14 NA TUBAL SCIENCE [May 



variations. These being now known, it is at once seen that Natural 

 Selection plays no part at all in causing them. 



If I sow a quantity of seed of the wild carrot, radish or parsnip 

 in a rich garden soil, and at the end of the season select and pull 

 up all the individuals with roots having the same size as, or less than 

 one-half larger in diameter than those of plants growing wild, leav- 

 ing all with roots at least half as large again as the wild ones, — 

 what has my selection and rejection of the former to do with the 

 cause of- the swelling of the roots of those individuals I consider 

 to be the fittest to survive ? 



This, it appears to me, would pretty accurately illustrate Mr 

 Tayler's and Neo-Darwinians' arguments. 



Again, he says, " it is apparently assumed by Henslow that 

 variations, being always definite, upset the Darwinian position." 

 Such, at least, was the opinion of Eomanes, who wrote me as 

 follows : — " Of course, if you could prove that indiscriminate varia- 

 tions have not occurred in wild plants . . . you would destroy 

 Darwinism in toto." No one can be called upon " to prove a nega- 

 tive," but I am told by many that my books do prove the contrary, 

 that variations are definite. Darwinism is, of course, absolutely 

 based on the supposed existence of indefinite variations, otherwise 

 there would be nothing for Natural Selection to do for it. 



Mr Tayler alludes to a prevalent " contempt for theory." I am 

 not aware of such ; but there undoubtedly exists a strong tendency 

 to reject a priori assumptions, oftered without a particle of fact. 

 Thus, Mr Tayler writes : — " Assume that at any period, however 

 remote, variations were completely indefinite," &c. ; and then follows 

 a paragraph full of assumptions containing the words " assume " 

 twice, "suppose" once, "would" five times, "might" twice. It 

 is, therefore, needless to follow him, as the paragraph consists solely 

 of it priori statements (but no theory), for which he offers no basis 

 of facts whatever. 



The result of this argumentation on indefinite variations is a 

 strange one, viz., that "Definite variations would be precisely what 

 on a 'priori grounds woidd be expected." 



If this be so, how was it that neither Darwin nor Dr Wallace 

 ever expected them ? Darwin admits them, but puts them on one 

 side as rare or insignificant ; while Dr AVallace said he did not even 

 understand the meaning of the terms " definite " and " indefinite," 

 until I pointed out that they were not mine but Darwin's own, and 

 that the whole of Darwin's theory is based on the imaginary — unproven 

 — assumption of plants always varying indefinitely in nature. 



Darwin has really blended together two quite distinct things :— 

 (1) The origin of actual variations in organisms, as they occur in 

 nature ; a physiological work which can be seen going on slowly or 



