282 Non-I salable Races. 
whole set of facts. The variegated sorts are nearly all 
more or less constant; sometimes to a very small and 
sometimes to a very large extent. This character has 
been subjected to what we may call an automatic selec- 
tion, for every gardener naturally plants out only varie- 
gated specimens neglecting the green ones; also it is 
customary to cut away the green twigs which arise by 
bud-variation. Here we have a sort of unconscious se- 
lection which has however been exercised in the same 
direction for many years, and in many cases through 
some centuries. 
And what has been effected by this continued selec- 
tion? Absolutely nothing. At least, so far as we know, 
nothing more than maintaining the variegated varieties 
and keeping them in a fairly pure condition. But nothing 
like fixation has resulted ; that is to say, the varieties 
continue to produce atavists when grown from seed, and 
moreover, the pure and constant varieties which corre- 
spond to them have not been obtained. For in this case 
these varieties, as we stated above, would have to be the 
pure yellow ones, such as are known to gardeners under 
the name of aurea forms. 
All in all there are in our gardens, perhaps twenty 
or thirty, or even a few more of these anrca forms; and 
this number is as nothing compared with the almost un- 
limited series of variegated forms. Moreover exactly 
those variegated forms which have been cultivated most 
carefully and for the longest time have not given rise to 
aurea varieties. 1 
From this discussion I draw the conclusion that con- 
tinued selection with variegated plants will not of itself 
lead to the production of constant forms. For this, 
1 See the list on page 270. 
