Variegated Leaves. 275 
different from that of the typical form, but as soon as 
reversion occurs through bud-variation all these second- 
ary characters are dispersed at once, the green leaves be- 
coming flattened out, assuming the normal form, and 
often attaining twice the size of the variegated ones. In 
this way the reverted branch easily strikes the eye. I ob- 
served this most beautifully in Castanea vesca and Ulmus 
campestris, but Kerria japonica and many other species 
show it as well. 
The question which buds are most likely to give rise 
to atavistic branches has been much discussed, and the 
general opinion seems to be that the rhizome and the 
adventitious buds on the roots are most prone to rever- 
sion. Thus Glechoma hederaceuin variegatum often pro- 
duces green runners 1 whereas the variegated Tussilago 
Farfara breeds true from its runners. For the last ten 
years I have had a variegated plant of Rub us fruticosus 
which has produced both green and variegated plants 
from its radical buds in proportions which vary according 
to conditions, and to the year. It seems to me probable 
that the weaker buds are most likely to give rise to ata- 
vists ; but since this results in the production of green 
branches which grow much more vigorously than the 
neighboring variegated ones, it is not easy to decide this 
point. 2 
Variegated branches on green plants are almost as 
common. It is the general idea amongst gardeners that 
the numerous variegated varieties of woody plants have, 
with few exceptions, arisen in this way. One of these 
'VERLOT, loc. tit., p. 78. 
2 In papers on this subject we often come across an expression 
of the opinion that it is the strongest branches which become green; 
but this view, no doubt, is largely due to a misapprehension of the 
relation between the cause and its effect, as explained in the text. 
