480 DISEASED GEAPTS WILL CONTINUE DISEASE. 



author observes — " The Eanunculus will last about twenty or 

 twenty-five years in perfection, after which it degenerates and 

 perishes." It does not appear that this period of duration is 

 confined only to seminal varieties of vegetables, for although 

 the original wild parent still continues to flourish, as it has 

 done since its creation, yet there is no evidence to show that 

 the wild individuals are each more long-lived than those which 

 are domesticated. The fact appears to be that Anemones and 

 Ranunculuses are very short-lived species. In a wild state 

 they are annually renewed by self-sowing; in gardens they 

 enjoy a forced extension of vitality secured by artificial means, 

 which are, however, temporary in their effect, just as annuals 

 may be made to live for two or three years by similar means. 



In like manner when we are told that grafts taken from an 

 old ■ diseased fruit-tree produce young diseased plants, as is 

 undoubtedly the case, it is not to be inferred that its race is 

 wearing out. The only inference which the fact justifies is 

 that when an individual becomes diseased, a limb from that 

 individual, if transferred to another plant, carries its disease 

 with it. To prove the theory of degeneracy it is necessary to 

 show, what has never yet been done, that no care can preserve 

 a perennial variety from decrepitude. 



In the case of the Apple-trees and Gooseberry-bushes lately 

 adverted to this seems to be the true explanation of the facts 

 relating to them. A tree, from some cause or other, becomes 

 unhealthy; a piece cut from it and put upon another tree 

 carries its disease with it ; again divided, the disease is again 

 propagated, and this will go on as long as the unhealthy plants 

 remain exposed to the influences which originally caused 

 their bad health. But change the circumstances, place the 

 plants under more favourable circumstances, keep off the cause 

 of the evil, and the evil will gradually disappear, as has actually 

 happened to our diseased fruit-trees when carried to better 

 climates than our own. 



The best recent statement, witli which I am acquainted, of facts in 

 favour of wearing out will he found in a paper communicated to the 

 Gardeners' Chronicle (1853, p. 372) by Mr, Masters of Canterbmy. 



