6 BULLETIN 815, U. S. DEPARTMENT OF AGRICULTURE. 
an entire year had been obtained, it was transferred to a form having 
sufficient space for assembling the data of the individual tree for a 
period of several years. These performance-record forms, together 
with a more detailed account of the methods of compiling the rec- 
ords, are shown in United States Department of Agriculture Bulletin 
813, entitled ‘‘Citrus-Fruit Improvement: A Study of Bud Variation 
in the Eureka Lemon.”’ 
DESCRIPTIONS OF THE IMPORTANT STRAINS. 
LISBON STRAIN. 
The Lisbon strain was originally called the Semidense Productive © 
strain, on account of its habit of growth and productiveness. From 
the fact that the habit of growth of the trees and the characteristics 
of the fruits of this strain most nearly resemble the established ideal 
Fic. 1.—A typical lemon tree of the Lisbon strain (25 years old), No. 1-28-14 in the performance-record 
plat, showing the dense appearance of the foliage. The summarized record of this tree is presented in 
rank 23in Table I. 
for the Lisbon variety, it has been decided to callit the Lisbon strain. 
The trees of this strain are more productive than those of any other 
strain of the variety. The bulk of the crop reaches the necessary 
size for picking during the winter and spring seasons. 
The habit of growth of the trees is spreading, as shown in figure 1, 
and more or less upright. The fruits are largely borne on the inside 
of the tree and are protected from climatic injuries by the covering of 
rather dense dark-green leaves. The leaves are of medium size, 
oval in shape, obtuse, slightly crenate, abundant, and from deep to 
dark green in color. The flowers are usually perfect. , 
