7o 



EVOLUTION, GENETICS. AND EUGENICS 



changed conditions of life, an organ which was previously useful 

 becomes useless, it will be suffered to dwindle away in successive 

 generations, under the influence of certain natural causes which we 

 shall have to consider in future chapters. On the other hand, the 

 theory of special creation can only maintain that these rudiments are 

 formed for the sake of adhering to an ideal type. Now, here again 

 the former theory appears to be triumphant over the latter; for, 

 without waiting to dispute the wisdom of making dwarfed and useless 

 structures merely for the whimsical motive assigned, surely if such a 



F^/K 



RtJDiptCflTAp.y HttfD-LlpiBS 



A. \lEfiT, 



8. HOMy TEW/VflTIO/J or 



JllflD-LipMi. 



Fig. 7. — Rudimentary or vestigial hind limbs of python, as exhibited in the 

 skeleton and on the external surface of the animal. Drawn from nature, J nat. 

 size. {From Romanes.) 



method were adopted in so many cases, we should expect that in con- 

 sistency it would be adopted in all cases. This reasonable expectation, 

 however, is far from being realized. We have already seen that in 

 numberless cases, such as that of the fore-limbs of serpents, no vestige 

 of a rudiment is present. But the vacillating policy in the matter of 

 rudiments does not end here; for it is shown in a still more aggravated 

 form where within the limits of the same natural groups of organisms 

 a rudiment is sometimes present and sometimes absent. For instance, 

 although in nearly all the numerous species of snakes there are 

 no vestiges of limbs, in the Python we find very tiny rudiments of 

 the hind-limbs (Fig. 7). Now, is it a worthy conception of Deity 

 that, while neglecting to maintain his unity of ideal in the case of 



