98 Permanence and Evolution. 



forms with the adult state of others, that our 

 tests are very imperfect. The ova of all 

 mammals are, at the earliest stage of growth, 

 indistinguishable, yet they turn into dogs, cattle, 

 human beings, whales, etc. Now when two 

 objects, apparently indistinguishable, yet under 

 the same circumstances behave differently, there 

 must be some cause for this ; if we believe in 

 a specific vital force as the cause of organisation, 

 then we may perfectly suppose that the ova 

 of man, cow, and dog are materially identical, 

 but if we reject the conception of vitality as 

 something sni generis, then we are shut up to 

 believe that these ova, though with our present 

 tests indistinguishable, are really in some way 

 physically different. If it is not one way, it 

 must be the other ; N and for my present purpose 

 it is quite indifferent which of these two views 

 is the truth. 



So the stripes of the lion whelp resemble 

 to apparent identity those of the adult tiger ; 



