FLORIDA STATE HORTICULTURAL SOCIETY. 
41 
ceedingly minute variations in form, size 
color, fragrance, precocity and a thousand 
other characters which the practiced 
breeder perceives by a lightning like 
glance. The work is not easy, requiring 
an exceedingly keen perception of minute 
differences, great practice, and extreme 
care in treating the organisms operated 
upon, and even with all the naturally 
acquired variations added to those secured 
by scientific crossing and numerous other 
means the careful accumulation of slight 
individual differences through many 
generations is imperative after which sev¬ 
eral generations are often but not always 
necessai*y to thoroughly “fix” the desired 
type for all practical purposes. 
The above applies to Anuuals. or those 
plants reproduced by seed. The breeder 
of plants which can be reproduced by div¬ 
ision has great advantage, for any valuable 
individual variation can be multiplied to 
any extent desired without the extreme 
care necessary in fixing by linear breeding 
the one which must be reproduced by seed. 
But even in breeding perennials the first 
deviations from the original form are 
often unappreciable to the perception, but 
by accumulating the most minute dif¬ 
ferences through many generations the 
deviation from the original form is often 
astounding.” 
“By crossing different species we can 
form more variations and mutations in 
half a dozen generations than will be de¬ 
veloped by ordinary variation in a hun¬ 
dred or even a thousand generations. 
The evolution of species is largely depend¬ 
ent on crossing the variations contained 
within it. Forms too closely bred soon 
run out, because generally only by cross¬ 
ing does variation appear. 
It is of great advantage to have the 
parents a certain distance apart in their 
hereditary tendencies. If too close to¬ 
gether, there is not range enough of varie¬ 
ty. If too far apart the developed forms 
are unfitted for existence because too un¬ 
stable. Radical changes of environment 
for a series of generations will produce a 
tendency to sport, but hybridization will 
bring it about far more abruptly and for 
practical plant or animal breeding or for 
scientific study of all these variations, far 
more satisfactorily.” 
Mr. Burbank asserts there is a close 
analogy l)etween hybridization and graft¬ 
ing. An instance is cited in which Primus 
myrobalana Var. Pissardi was imported 
from France and grafted on the Kelsey 
plum, a variety of Primus Triflora. The 
graft did not bloom, but its presence on 
the tree brought about a cross between tJie 
two species. Many hundred descendants 
of this cross are now living. 
These remarks of Mr. Burbank’s on 
other plants show how slow and difficult 
will be the process of developing early 
and hardy oranges from hybrids and 
crosses. The chances are very small of 
anything of market merit in the first seed¬ 
lings and selective crosses of the improved 
hybrids and testing of hundreds and even 
thousands of their successive offspring 
may be necessary before the object is 
achieved. 
I therefore turn to the w’ork of another 
Californian whose work was described 
some tim'e ago in the “Citrograph” in 
part as follows: 
“It has long been the popular feeling 
that the Washington navel orange is 
“good enough.” Consequently when Mr. 
A. C. Thomson, of Duarte, announced his 
Improved Navel there were many who 
doubted such a possibility. And when he 
told the modus operand! of its origin the 
doubters said “Oh, fie!” To produce a 
