22 PERMANENCE OF VEGETABLE FOR .11 8. 



13. Now besides these evident laws, another may be detected 

 by a little observation, that the beings produced from these 

 germs are in every essential respect similar to their parents: and 

 that thus, after many thousands of generations, every plant or 

 tree of the present day, may be regarded with certainty as having 

 had a representative, at the period of the creation of the vegeta- 

 tion which now clothes our globe. 



14. The exceptions which may seem to exist in regard to 

 this law are so in appearance only. The seeds of any particular 

 kind of Apple, for instance, will not produce the same kind with 

 any certainty, but are as likely to give origin to trees that shall 

 bear very different and far inferior fruit. The same be said of 

 the cultivated Dahlia, which presents so many beautiful varieties 

 of colour ; the seed of a white flower is not much more likely to 

 produce white Dahlias, than one with yellow or purple flowers. 

 But in these and many more such instances, the different kinds 

 are first produced by the influence of cultivation only, and had 

 all originally but one stock ; and it is this stock, common to all 

 kinds, which the seed has a tendency to perpetuate, rather than 

 any one of the varieties which have been obtained from it by the 

 art of man ; and we never find any tendency to produce a plant 

 of an entirely different kind. Thus, the sour Crab is the stock 

 of all the rich and delicate varieties of the Apple ; and if the 

 seeds of any of these be sown in a poor soil, the plant will bear 

 fruit resembling that of the original; but still it will be an Apple, 

 and never a Pear or a Quince, or any other of the kinds most 

 nearly allied. In the same manner, the original stock of the 

 Dahlia is a plant having a very ordinary yellow flower, with but 

 one circle of coloured florets ; but by the influence of cultivation 

 the number of these circles is much increased, and the colours 

 are deepened and enriched, as well as almost infinitely varied. 

 The seeds of any of these, however, when sown in a poor soil, 

 will produce a plant resembling the original parent ; and thus it 

 is seen that there is no real exception in such cases to the general 

 law, that the form of the species or distinct kind is propagated 

 without any important alteration through successive generations; 

 so that we may regard all the tribes of plants, really distinct 



