pendent wooden island. But if the flood gradually subsided, 

 lie would see, to his amazement, tie twigs unite to form 

 small branches, these again to form other branches, ter- 

 minal twigs reappearing which had been quite covered and 

 lost in the ilood, until at last he would discover that this 

 multifarious arrangement of spreading growth sprang from 

 "a common bole. 



Substitute for the terminal and unflooded twigs existing- 

 species, time for the flood, and extinct species for the 

 branches that were totally submerged, and you will have 

 no obscure conception of what is meant by descent. All 

 forms of animal and vegetable life have sprung from 

 one or a few simple sources, becoming more a»d more 

 complex and differentiated from each other in the vast 

 lapse of time, most forms becoming extinct, until the few 

 that survive are so widely separated, and so diverse in 

 structure and function, that their common origin has ceased 

 to be discernible, and their connecting links- are buried in 

 the past. 



But Organic Evolution ia one thing, and the doctrine of 

 Natural Selection is another. 



Natural Selection is a theory as to the nature of one, 

 perhaps of that one which is ohiefest, of the factors which 

 have produced the variation and development of species. 

 Charles Darwin, by twenty years of patient labour, suc- 

 ceeded in demonsti'ating much of the manner in which th& 

 evolution of living forms takes place. 



All animal and vegetable organisms tend to vary from 

 one another. When the forces of nutrition are super- 

 abundant they would appear to be irregularly disposed and 

 stored in the economy during that period of growth when the 

 income of the organism is greater than its expenditure, ancS 

 to become available for the production of new modifications. 

 The modifications chiefly, though not exehisively, arise when 

 the ancestral form having been, in the main, assumed, there 

 remains a superabundant vitality — a balance at the bank, as- 

 it were — efficient to theii* production. Such variations tend 

 to be transmitted from parent to offspring. 



It is by some knowledge of these facts that breeders, 

 florists and gardeners, produce their wonderful results- 

 It is by practical though half-unconscious application of 

 them, that the short-necked stumpy horse of primitive times 

 has been converted into the swift winner of the Derby ; 

 that crabs have bee^n turned into ribston-pippins ; grasses- 



