Practice of Plant Breeding 
hybrid walnut, for instance, planted in 1891 and said 
to have been 80 feet in height and 2 feet in diameter 
in 1906. The timber is also said to be of excellent 
quality. Such trees would solve all our forestry pro- 
blems. His stoneless plums, obtained from an old and 
useless French variety, would also be valuable, and so 
with many of the others. 
In forming his Alhambra plum he is said to have 
combined seven different varieties, which were grafted 
on old trees and so brought into bearing at the earliest 
possible moment. 
One can only hope that the spineless edible cactus 
with which he experimented for many years, and for 
which he crossed many different American species, will 
really prove hardy and useful in desert and half-desert 
places. 
During 1906, in the first six months of their life, 
some of these cacti produced 47} lbs. per plant which, 
as they were planted in rows 5 feet apart and 2} feet 
distant, has been estimated as a yield of 90 tons per 
acre. Even if this should prove unsuited for cattle- 
feeding, it will surely be of value, perhaps, for the pro- 
duction of alcohol. It is unnecessary to describe in 
detail the Shasta daisies, the Cannas 7 inches across, 
and the huge Amaryllis and other flowering plants which 
have been produced by him. 
In breeding lilies he is said to have used 500,000 
plants in one single test.* 
He was not, however, always successful. In his 
efforts to improve the Californian dewberry, he crossed 
it with brambles, with rasps, strawberries, roses, cherries, 
apples, and pears and never got any satisfactory result. 
Hundreds of Nicotianas were crossed with Petunia, but 
* This account of Luther Burbank’s life and work is entirely derived from 
books and publications. The author has never seen any of his novelties. 
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