8 DARWINISM. 



their immediate offspring are, it is true, comparatively 

 slight. It would, indeed, be a prodigious birth if one 

 family contained at once a young monkey, a little pig, 

 a big donkey, and a great goose; but it is obviously 

 possible that any amount of unlikeness may be found 

 between the descendants of common ancestors, if we are 

 not confined to the differences of a single generation, 

 but are allowed to multiply them through as many 

 thousands as we require. Say that two race-courses 

 differ in length by one yard; multiply that difference 

 1760 times and they will then differ by a whole mile. 

 If, on leaving this Lecture-room, you found the trees 

 which half-an-hour ago were bare and leafless clothed 

 with summer verdure, your gardens blooming with a 

 wealth of roses, your orchards laden with autumnal 

 fruits, you would scarcely credit your senses; and yet, 

 when the requisite number of half-hours, reckoned by 

 days and months, shall have elapsed, you will greet 

 these wonderful changes as perfectly natural and nothing 

 to be wondered at. In a dissolving view that is well 

 managed, Alpine peak and glacier-pass melt impercep- 

 tibly into some tall cathedral and sunshiny market- 

 place. The two scenes are wholly unlike, and yet it is 

 contrived that at* no moment should the passage from 

 one to the other be discernibly abrupt. Is it not 

 possible then to conceive that through an immense 

 multitude of generations the form of an ape might be 

 derived from the form of a fish ? We do not mean to 

 say that this has actually happened, but supposing the 

 descendant of the fish to vary continuously in the direc- 



