178 APPLICATION OF PRIlsrciPLES. 



should be preserved . for long periods of time : tlie 

 power of conveying them for great distances, through 

 various climates, is one of those upon which man most 

 depends for the improvement of the horticultural re- 

 sources of all countries; and for this purpose large 

 sums are annually expended, both by governments 

 and individuals. It is, therefore, an object of the first 

 importance to ascertain, what is not well understood, 

 as it would seem, namely, the causes by which the 

 destruction of the germinating power of seeds is 

 effected ; for it is only by doing this that their pre- 

 servation can be secured. 



Seeds are probably possessed of different powers of 

 life, some preserving their vital principle through 

 centuries of time, while others have but an epheme- 

 ral existence under any circumstances. The reasons 

 for this difference are unknown to us, and apparently 

 depend upon a first cause, over which we have, 

 therefore, no control ; but the fact of great longevity 

 in some seeds is certain, and there seems no reason 

 why the conditions which enable them to preserve 

 their germinating power for long periods of time 

 should not be discovered and imitated. 



Without admitting such doubtful cases as those of 

 seeds preserved in mummies having germinated, there 

 are many instances of seminal longevity about which 

 there can be no doubt. Books contain an abundance 

 of instances of plants having suddenly sprung up from 

 the soil obtained from deep excavations, where the 

 seeds must be supposed to have been buried for ages. 

 Professor Henslow says that in the fens of Cambridge- 



