^ ANIMAL MECHANISM. 



the surprising variety of living beings, has already furnished 

 important arguments in favour of development. But many 

 NUT, ml* look with suspicion on these studies; they consider 

 that the immutability and variability of animal species belong 

 t< rhe domain of insoluble questions. 



It is true, that if we ask the partizans of development to 

 prove experimentally the reality of their doctrine ; if we 

 n quire of them, for example, to transform the ass specic-s into 

 the horse or anything analogous to it, they are forced to avow 

 their inability, and they reply that it is necessary, in order 

 to (.'fleet this, to exercise modifying influences during millions 

 on millions of years. It must indeed have been by very slow 

 transitions that the variation of species has been effected, if it 

 indeed has taken place. Consequently, in the absence of an 

 experimental solution, the development hypothesis can neither 

 be proved nor refuted. 



Learned men, whose minds are habituated to rigorous de- 

 monstration, are not interested in such questions ; they have 

 no scientific value in their estimation. And yet science meets 

 with such every day. When an astronomer studies the in- 

 fluences which may cause the heavenly bodies to move more 

 slowly; when he predicts a modification of the orbit of tho 

 earth after the lapse of some millions of years, or a lengthen- 

 ing of the period of rotation of our planet changes which 

 would affect all the inhabitants of the earth with a mortal 

 chill this philosopher is listened to. When he speaks of a 

 i iH^e, however slight it may be, of the retardation of a 

 planetary movement, every one understands that if this cause 

 should continue during many ages, its effects will be exag- 

 -. era ted by the lapse of time. No one tells this astronomer 

 to \\ait till some millions of years have proved tho accuracy of 



Why should () be more unjust to the theory of develop- 

 ment ' J . It cannot, it is said, bring before our eyes the trans- 

 I iiuation of one animal into another. This is true, but it 

 may show us some tendency to this transformation. However 

 .slight it may In-, M-( accumulating more and more during 

 many ages, it may bec..ine as complete a transformation as 

 \\ 6 can imagine. 



