476 SOME PLANTS ARE NATURALLY SHORT LIVED. 



All who understand the nature of plants, and the manner in 

 which they grow, and have witnessed that incessant renewal 

 of their vitality with which Providence has so wonderfully 

 endowed them, would hesitate to adopt Knight's views except 

 in the presence of facts capable of no other possible inter- 

 pretation. No physiologist can separate the nature of what 

 gardeners call varieties (of course mules are not here included), 

 from that of a wild race. In their intrinsic quahties they are 

 the same. It can make no difference in the nature of a plant 

 whether it is sown by a gardener or by winds, birds, animals, 

 or other agents. The Oak which springs up in a forest is not 

 in the smallest physiological particular different from that 

 which rises from the bed of a nurseryman. The Cabbages 

 which load the waggons of a market gardener are in their 

 essence the same as those which sprout forth from the sea- 

 beaten cliffs of the ocean. They may be greener or redder, 

 more succulent and larger; but they are physiologically the 

 same. We therefore must dismiss from our argument the 

 word variety, which only leads to a confusion of ideas. 



Among plants, as among animals, there are ephemeral and 

 perennial species. The butterfly perishes in a few hours; 

 nothing can defer the arrival of that early death which is the 

 portion of such beings. Man, on the contrary, is endowed with a 

 longevity the limit of which is hardly definable. In plants we 

 have annuals, biennials, and perennials, to the last, of which 

 belong all trees and bushes. Now, wild perennial plants, 

 whether woody or herbaceous, whether forming a trunk or a 

 mere permanent root, have never yet been shown by any trust- 

 worthy evidence to be subject to decrepitude, arising from old 

 age. On the contrary, every new annual growth is, as has just 

 been stated, an absolute renewal of their vitality, in the absence 

 of disturbing causes. Hence the enormous age at which trees 

 arrive. A thousand years is still youth to a forest-tree which 

 no accident has injured; and there is no intelligible reason 

 why it should not, if guarded from violence, continue to grow 

 to eternity. Travellers believe that they have found, in the 

 forests of Brazil, trees that were seedlings in the age of Homer. 

 There seems to be no doubt that the WeUingtonias, now 



