84s LECTURES ON EVOLUTION m 



there will be modification of change and 

 form. 



Thus the existence of these persistent types, as 

 I have termed them, is no real obstacle in the way 

 of the theory of evolution. Take the case of the 

 scorpions to which I have just referred. No 

 doubt, since the Carboniferous epoch, conditions 

 have always obtained, such as existed when the 

 scorpions of that epoch flourished ; conditions in 

 which scorpions find themselves better off, more 

 competent to deal with the difficulties in their way, 

 than any variation from the scorpion type which they 

 may have produced; and, for that reason, the scorpion 

 type has persisted, and has not been supplanted by 

 any other form. And there is no reason, in the 

 nature of things, why, as long as this world exists, if 

 there be conditions more favourable to scorpions 

 than to any variation which may arise from them, 

 these forms of life should not persist. 



Therefore, the stock objection to the hypothesis 

 of evolution, based on the long duration of certain 

 animal and vegetable types, is no objection at all. 

 The facts of this character and they are numer- 

 ous belong to that class of evidence which I have 

 called indifferent. That is to say, they may afford 

 no direct support to the doctrine of evolution, but 

 they are capable of being interpreted in perfect 

 consistency with it. 



There is another order of facts belonging to the 

 class of negative or indifferent evidence. The 



