APPENDIX. 603 



similar conditions, as invariably fail to grow. The lesson to be learned 

 from these observations by the propagator in his grafting and hybridising 

 operations is, that a wide view of a species or variety must be taken, and 

 if any two individuals fail, after having been operated on reciprocally, 

 others must be selected, and every little variation in light, heat, air, and 

 nutrition must be studied, and then we shall hear of fewer failures than is 

 now the case. 



Much has been written by Darwin and others on the non-permanence 

 of varieties ; but the supposed disappearance of these is often reappearance 

 under a new name, as shown in the following extract from the ' Gardeners' 

 Chronicle' (1876, p. 396) : 



" The disappearance of varieties is no proof whatever that they have died 

 out. Varieties are being superseded almost daily, but supercession is no 

 proof of decrepitude or weakness. Novelty alone, and the increasing love 

 of it, is constantly treading down older varieties. Improvement is at work 

 in the same direction ; every accession of new vigour threatens to ex- 

 tinguish older and less powerful varieties by asserting and perpetuating 

 the supremacy of the strongest. The survival of the fittest means, when 

 left to the operation of natural laws, the suppression and extinction of the 

 weakest. Those and other influences are always at work to cause varieties 

 to disappear, and that independently of any inherent tendency in them- 

 selves to die out. 



" It is impossible to estimate the potency of altered conditions, abnormal 

 developments of particular parts for special purposes, high or unnatural 

 means of cultivation ; exhausted soils, and consequent semi-starvation ; 

 tendencies to revert backwards, and others equally powerful, perhaps, to 

 run forward, and break or sport into new forms, colours, sizes. These 

 and other influences all lead to change of varieties, wholly independent of 

 their dying out. As we try to measure their potency, and enter into their 

 ceaseless activity and mysterious modes of bringing about changes, the 

 marvel is, not that so many varieties have disappeared, but that so many 

 remain constant. Vital force is somewhat like a spirited horse : it is 

 closely and thoroughly harnessed by certain laws to reproduce its like, but 

 every now and again it kicks over the traces, and leaves as the footprints 

 of its erratic outbreaks a new variety. It may be better or more service- 

 able, assuredly it is newer than the old. In this last, combined with the 

 love of novelty in men, amounting pretty well to a passion, we have a 

 security for the careful conservation of the novelty, and it may be in con- 

 sequence a contemporaneous neglect of the older variety. Therefore the 

 disappearance of old sorts is no proof whatever that they have died out, 

 while, on the other hand, their continuance is a sure and certain proof of 

 their stability. 



* ' Dr Asa Gray endeavours to establish a distinction between the dura- 

 bility of varieties increased by seed and those propagated by buds or off- 

 sets, and considers that the former are likely to be more permanent than 

 the latter, inasmuch as cross-breeding, as illustrated by Darwinism, was 

 appointed not merely to perpetuate and increase the numbers of plants, 

 but also to reprime them with steadying force to prove the constancy of 

 varieties. It is based upon the fact, so clearly illustrated by Mr Darwin, 

 that cross-fertilisation is Nature's rule of propagating varieties ; and the 

 inference for the argument here is nothing more is, that consequently it 

 is the mode that assures most stability, else Nature would not have pro- 

 vided so much and so many admirable adaptations to insure this particular 

 mode of increase. This, however, is begging most of the question ; we 

 know next to nothing of the why and wherefore of any of Nature's 

 proceedings ; even Mr Darwin, the most careful observer and lucid 



