280 Non-Isolable Races. 
plants are often entirely green during years of improper 
treatment, but with due care can be restored to the varie- 
gated condition. 1 
The degree of variegation is not only dependent upon 
the conditions of growth but also on the time of the year. 
If we look closely at variegated plants in green-houses 
we shall see that the branches which arise in summer are 
beautifully flecked, whereas those which arise in winter, 
when they get less light, are much greener and sometimes 
even quite green. This at least is true in our climate; 
but one must remember that the leaves formed in sum- 
mer remain on the shrubs through the winter, and 
undergo no further change in their variegation. There- 
fore it is not the general appearance which is dependent 
on the time of the year. Quercus pedunculata argcntco- 
picta is green in spring, but becomes white or variegated 
later on. 2 Young plants are often still green in spring 
even though later they may become variegated, as for 
instance, Symphytum, Barbarea vulgaris, etc. 3 I have 
observed in a culture of Geum urbanum, which I have 
kept up during several years, that the variegated speci- 
mens gradually develop green leaves in the autumn and 
lose the variegated ones. In winter they were almost 
completely green, but as soon as life awoke in the spring 
they began to develop flecked leaves again, and through- 
out the whole summer they were fully variegated. They 
behaved in this way throughout every winter of their 
life. On the other hand a variety of the ornamental 
curly cale with yellow-veined leaves is beautifully varie- 
1 VERLOT, loc. cit., p. 75. 
2 L. BEISSNER, Knospenvariation, Mitth. d. deutsch. Dendrolog. 
Gesellsch., No. 4, 1895. 
3 VERLOT, loc. cit., p. 76. 
