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reached their present stage of development by long con- 

 tinued selection, generally by a considerable number of 

 breeders and consequent accumulation on diverse lines of 

 those small individual difierences which characterize seed- 

 lings. These differences being transmitted by inheritance, 

 and occasionally enhanced by what may be termed minor 

 sports, amounting eventually to such a transformation that 

 no outsider would impute them to their original parents. 

 As this accumulation of character occurs entirely under 

 culture, we may justifiably term the plants so obtained 

 " garden varieties." We may equally justly apply the term 

 to another large section of floricultural exhibits obtained by 

 hybridization, since in both cases the types are due to 

 human agency, controlling in certain directions the innate 

 tendency to variation in the one case and the power of 

 combination in the other case, while protecting the result- 

 ing plants from that purely natural selection which would 

 probably result in the destruction of most of them. As a 

 consequence of so much divergence of type being brought 

 about by these selective and combining operations in culti- 

 vators' hands, the opinion has gradually been strengthened 

 that it is culture which is the cause of the variability 

 displayed, more especially as the behaviour of purely wild 

 plants under purely natural conditions is comparatively 

 little studied and practically (with one exception) not at all 

 by cultivators for the market so as to admit of a proper 

 comparison of the two plant sections, viz. the wild and the 

 cultivated, as regards their relative variability. The one 

 exception exists in the case of our native wild Ferns, 

 which have now been my special study for over a quarter of 

 a century, and which represent absolutely the only group 

 of genera and species which, in their purely wild state, have 

 been subjected to singularly close scrutiny by a consider- 

 able number of skilled observers for over half a century. 

 These observers have devoted their attention to the dis- 

 covery among wild plants of ''sports," or markedly 

 distinct abnormal forms, and, thanks to a few of the most 

 prominent ones, a constant record has been kept of their 



