ARTIFICIAL AND NATURAL SELECTION 29 



doubt, and resting on incomplete observations. The main conclu- 

 sions, however, seem to be quite clear, since they are always the same. 

 Sudden sports cannot be denied to be the chief, and probably the sole, 

 method of the origination of new horticultural forms. 



There is, however, another, more weighty objection. The facts 

 collected by Korshinsky pertain to varieties, and not to true species. 

 Most of the varieties, and especially of the horticultural varieties, owe 

 their origin to retrograde changes, to the apparent loss of some previ- 

 ously acquired character. Besides these, no doubt, there are other 

 types, but these may be considered as of a degressive nature. Ancient 

 characters, once lost, may reappear, and produce the impression of 

 something quite new, whilst in reality they are only the reviving 

 of some old latent quality. From a critical point of view the facts 

 collected by Korshinsky may prove the sudden origin of new varieties 

 by the loss of characters or by the revival of apparently lost ones; 

 but they do not afford any cases of really progressive steps. 



Systematic evidence has to guide us on this most important point. 

 The subdivisions of the species afford the material for a closer study 

 of progressive evolution. In some cases they comply with the type of 

 horticultural variability, one form constituting a primary t}>-pe, from 

 which the remaining have obviously been derived. Such derivations 

 are usually of a retrograde nature, consisting in the loss of color, of 

 hairs, of spines, of wax on the surface, or of other distinct marks. 

 Sometimes, however, they are degressive, indicating the reappear- 

 ance of some latent peculiarity, and thereby seeming to repeat the 

 characters displayed by some allied but distinct species. 



In most of the cases, however, the relation between the lesser units, 

 constituting a systematic species, is of another nature. They are 

 all of equal importance. From one another they are distinguished by 

 more than one mark, often by slight differences in nearly all their 

 organs and qualities. Such forms have come to be designated as 

 elementary species. Varieties they are only in the broad and vague 

 significance of the word. 



In some cases these different forms of the same systematic 

 species are found in distant localities. The representatives of the same 

 type from different countries or regions do not exactly agree, when 

 compared with one another. Many species of ferns afford instances 

 of this rule, and Lindley and other great systematists have often 

 been puzzled by the wide degree of difference between the members 

 of one single group. 



In other instances the subspecies are observed to grow nearer to 

 each other, sometimes in neighboring provinces, sometimes in the 

 same locality, growing and flowering in mixtures of two or three, 

 or even more, elementary species. The violets exhibit some wide- 

 spread ancient types from which the numerous local species may be 



