Definite Variation 101 



as not, I suspect rather of the nature of tool-marks, mere incidents 

 of manufacture, benefiting their possessor not more than the wire- 

 marks in a sheet of paper, or the ribbing on the bottom of an oriental 

 plate renders those objects more attractive in our eyes. 



If Variation may be in any way definite, the question once more 

 arises, may it not be definite in direction ? The belief that it is has 

 had many supporters, from Lamarck onwards, who held that it was 

 guided by need, and others who, like Nageli, while laying no emphasis 

 on need, yet were convinced that there was guidance of some kind. 

 The latter view under the name of "Orthogenesis," devised I believe 

 by Eimer, at the present day commends itself to some naturalists. 

 The objection to such a suggestion is of course that no fragment of 

 real evidence can be produced in its support. On the other hand, / / 



with the experimental proof that variation consists largely in the "", , 

 unpacking and repacking of an original complexity, it is not so certain 

 as we might like to think that the order of these events is not 

 pre-determined. For instance the original "pack" may have been 

 made in such a way that at the nth division of the germ-cells of a 

 Sweet Pea a colour-factor might be dropped, and that at the n + ri 

 division the hooded variety be given off, and so on. I see no ground 

 whatever for holding such a view, but in fairness the possibility should 

 not be forgotten, and in the light of modern research it scarcely looks 

 so absurdly improbable as before. 



No one can survey the work of recent years without perceiving 

 that evolutionary orthodoxy developed too fast, and that a great deal 

 has got to come down ; but this satisfaction at least remains, that in 

 the experimental methods which Mendel inaugurated, we have 

 means of reaching certainty in regard to the physiology of Heredity 

 and Variation upon which a more lasting structure may be built. 



