322 JOURNAL OF THE KOYAL HOKTI CULTURAL SOCIETY. 



which horticulturists call the fixing of a variety consists essentially in 

 a purification of the new form from the effects of intercrossing with its 

 neighbours. Insects are constantly carrying the pollen from one flower 

 to another. A novelty often makes its first appearance in only one 

 single specimen, and this, of course, will be exposed in a far greater 

 degree to the effects of foreign pollen than a small group of similar 

 plants would be. Next year, a considerable part of the seed will produce 

 "rogues," and these will have to be exterminated. Of course, this 

 process must be repeated during several years, for a longer or a shorter 

 period, according to the propensity of the species for self-fecundation or 

 for cross-pollination. 



Besides this most essential but purely practical aim of the process of 

 purification, there is, at least in many cases, a more intrinsic cause for 

 the need of young varieties to be fixed before being brought on the 

 market. At the moment of their first appearance, they often show no 

 more than a slight indication of the character they are able to display. 

 Double flowers may first appear as a slight dilation of a few stamens ; 

 variegated varieties may betray themselves by almost invisible white 

 spots on some leaves ; and so on. The variety has to pass through a 

 series of intermediate stages before it is sharply and clearly contrasted 

 with the species, so as to attract the attention of the amateur. 



A critical study of these well-known phenomena leads to the distinc- 

 tion of two types of varieties. They may be distinguished by the names 

 of constant and ever-sporting varieties. The first form is seen to be 

 produced at once, and is not connected with the original species otherwise 

 than by the products of accidental crosses. White flowers, as a rule, are 

 not the result of an often repeated, tedious and gareful selection of the 

 palest coloured individuals : they appear at once, unexpectedly and with- 

 out intermediates. Once produced, they are as constant and as true from 

 seed as the parent species itself. The same holds for dwarf varieties, and 

 for numerous other cases. The florist's work in fixing his novelty, in 

 reality, is nothing more than isolation or purification from the effects of 

 insufficient isolation. Complete isolation, whenever practicable, would 

 reach the effect of the whole process in a single year. 



On the other hand, we have the ever-sporting varieties. Their 

 variability is such that they often almost reach, or even transgress, the 

 limits of the parent type. Double-flowered varieties may produce at the 

 end of the season, on weak side branches or on stunted specimens, some 

 almost, or even wholly, single flowers. Variegation depends, in a large 

 measure, upon external influences, and the variegated horse-radish 

 (Cochlearia Armoracia) may produce pure white or unspotted green 

 leaves, according to the method of cultivation. Such an ever-sporting 

 variety may appear, at first, either in full development or in an extremely 

 small degree. In the latter case it has to be isolated and to be " worked 

 up " (as the phrase goes) before its full worth can be displayed. In such 

 cases the term "fixing" evidently has another theoretical meaning than 

 in the case of constant varieties, although the practical work may be the 

 same for both. 



In order to be able to study the real nature of these processes 

 thoroughly, it was necessary to observe the origin of new varieties under 



