SIVATHERIUM AND GIRAFFE. 



261 



extremely small in comparison with those which geology 

 allows for its phenomena. "Although/' says Mr. Hal- 

 demai, "we may not be able, artificially, to produce a 

 change beyond a definite point, it would be a hasty infer- 

 ence to suppose that a physical agent acting gradually for 

 ages, could not carry the variation a step or two further." 



I may here advert to a fallacy which has been one of 

 the principal difficulties in the way of the supposition of 

 every kind of transmutation. It is always taken for 

 granted that the parental animal must be extinguished in 

 consequence of the change. Thus we find a suggestion 

 by M. St. Hilaire that the modern giraffe may be a modifi- 

 cation of the sivatherium of the Indian tertiaries, met very 

 complacently by a reference to the discovery of Dr. Fal- 

 coner, that in these tertiaries, the giraffe is associated with 

 the sivatherium. So also the suggestion that the hare of 

 Siberia, with its curtailed ears, shorter hind legs, and ab- 

 sence of tail, may be a modification of the ordinary hare, 

 has been answered by Professor Owen, with a reference to 

 the fact that the tailless hare (Lagomys Spelaeus) is found 

 as early in the tertiaries as any species of the true genus, 

 Lepus.* Now it is entirely an assumption on the part oi 

 those who oppose the transmutation theory, that the orig- 

 inal animal shall perish when the new one is produced ; 

 and therefore the difficulty is entirely of their own making. 

 The probable fact is that the modification takes place in 

 an offshoot of the original tribe, which has removed into a 

 different set of circumstances, these circumstances being 

 the cause of the change : thus there is no need to presume 

 that the original tribe is at all affected "by any such modifi- 

 cation. The case is precisely analogous to that of a colony. 

 We see, for example, the New Englanders change from 

 the original English type, without any necessary effect 

 upon the parent stock. Just so might the giraffe be a 

 changed sivatherium, and yet the sivatherium continue to 

 exist. And in point of fact, there are many animals now 

 living along with their disposed modified descendants. 

 Unless, therefore, it could be proved that the supposed 

 descendant actually preceded in date the animal from 

 which it was said to have sprung, objections of this na- 

 ture can be of no force. The reader will understand that 

 1 only adduce the instances of the sivatherium and hare 

 for the sake of illustration, and without undertaking to 

 * British Fossil Mammalia and Birds, p. 215. 



