OBJECTIONS TO THE THEORY OF DESCENT. 343 



UNNECESSARY TO EXPLAIN THE CAUSE OF EACH INDI- 

 VIDUAL DIFFERENCE. 



Animals and I n accordance with the views maintained 

 Plants, vol. by me in this work and elsewhere, not only 

 », page o. ^ e various domestic races, but the most dis- 

 tinct genera and orders within the same great class — for 

 instance, mammals, birds, reptiles, and fishes — are all 

 the descendants of one common progenitor, and we must 

 admit that the whole vast amount of difference between 

 these forms has primarily arisen from simple variability. 

 To consider the subject under this point of view is enough 

 to strike one dumb with amazement. But our amaze- 

 ment ought to be lessened when we reflect that beings 

 almost infinite in number, during an almost infinite lapse 

 of time, have often had their whole organization rendered 

 in some degree plastic, and that each slight modification 

 of structure which was in any way beneficial under ex- 

 cessively complex conditions of life has been preserved, 

 while each which was in any way injurious has been 

 rigorously destroyed. And the long-continued accumu- 

 lation of beneficial variations will infallibly have led to 

 structures as diversified, as beautifully adapted for various 

 purposes and as excellently co-ordinated, as we see in the 

 animals and plants around us. Hence I have spoken of 

 selection as the paramount power, whether applied by 

 man to the formation of domestic breeds, or by nature to 

 the production of species. 



If an architect were to rear a noble and commodious 

 edifice, without the use of cut stone, by selecting from 

 the fragments at the base of a precipice wedge-formed 

 stones for his arches, elongated stones for his lintels, and 

 flat stones for his roof, we should admire his skill and 

 regard him as the paramount power. Now, the frag- 



