426 Rev. S. Haughton on the Origin of Species. 



both sides of the question with impartiahty." — Darwin's Origin 

 of Species, pp. 481-83. 



The theories of ^Loyevea-L^, already described, and many others, 

 are based upon the following three unwarrantable assumptions, 

 the denial of which, until proved, brings to the ground the 

 entire structure, like a child's house of cards — 



I. The indefinite variation of species continuously in the one 

 direction. 



II. That the causes of variation assigned, viz. cross-breeding 

 (Buffon), imitation (Lamarck), and natural advantage in the 

 struggle for existence (Darwin), are sufficient to account for the 

 effects asserted to be produced. 



III. That succession implies causation. 



On each of these a few words of explanation are necessary. 



I. The indefinite variation of species continuously in the one 

 direction. 



This has been expressed by some Lamarckians as a state 

 of unstable equilibrium of nature ; but should we assume the 

 existence of a law which is contrary to all we know of every 

 other department of nature ? If we must have a mechanical 

 analogy to fix our ideas, nature might be better compared to a 

 condition of dynamic equilibrium, in which all the parts are in 

 motion, and never return to precisely the same relative positions, 

 but, nevertheless, continually balance round certain definite 

 positions of equilibrium, which never change. What should we 

 think of the astronomer who, from a few years' observation of 

 the precession of the equinoxes, should predict that in due time 

 the north pole of the earth's axis would point to the same posi- 

 tion among the stars that the south pole now occupies? yet 

 this very species of assumption is made by Lamarck and Darwin, 

 in their appeal to the supposed influence of a long lapse of time. 

 Yet, in the writings of the latter progressionist there is this 

 singular inconsistency, that while he shows the utmost effects of 

 human breeding on domestic animals to be capable of produc- 

 tion in ten or twenty years, he denies the right of his adversaries 

 to appeal to the unaltered condition of the ass, the ostrich, or 

 the cat for 3000 years as a proof that specific forms balance 

 round central types, and have no tendency to depart indefinitely 

 from them. 



. Is it rational to suppose that man can alter the head and neck 

 of a pigeon into any desired form in six years, and that nature, 

 with her greater skill, cannot in 3000 years lengthen the ostrich's 

 wings by a single inch, although, according to the theory, it is 

 her evident wish to do so ? 



II. The causes of variation assigned are not adequate to pro- 

 duce the effects assigned to them, — The discussion of the inade- 



