Horticultural \\irieties Arisen Suddenly. 99 
new form are the only arguments for its sudden appear- 
ance. 
11. HORTICULTURAL VARIETIES WHICH HAVE ARISEN 
SUDDENLY. 
It is a matter of common knowledge that horticultural 
varieties have very often arisen by sports. But opinions 
differ on two points. One is an empirical one and relates 
to the question of constancy; the other relates to the 
meaning of the word variety. The two points are nar- 
rowly bound up with one another. If the new form is 
not constant and pure from seed but frequently reverts 
to the parent species it is usually supposed to be derived 
from that species and is treated as a subdivision of it. 
But if the new form is as constant as the parent species, 
the empirical means of demonstrating its relationship 
are lacking, and the conclusions are drawn from his- 
torical data and based on analogy; a proceeding which, 
as we all know, often leads to differences of opinion. 
Besides the historical records the main point in such 
cases is always the proof of the constancy from seed. 
But inasmuch as the interest of the practical man only 
extends to the question whether the variety can be con- 
veniently multiplied by seed and is not concerned with 
the possibility of occasional reversions, such information, 
especially in older cases, can only be accepted with cau- 
tion. 
\Yith this reservation, I propose to give a brief review 
of some of the better known instances. But before I 
do this I will call attention to a very beautiful variety 
which I have not yet found described nor seen in trade- 
catalogues, but which has appeared in my own cultures. 
