28 BULLETIN" 623, U. S. DEPARTMENT OF AGRICULTURE. 
to such as will, it is thought, illustrate the character and importance 
of the records. The complete data from the beginning of the inves- 
tigation until the present time are open for inspection at any con- 
venient time to all interested persons. The publication of the com- 
plete data would entail the presentation of such a large number of 
figures and tables as to make this bulletin cumbersome and in all 
probability defeat one of the objects of its issue, namely, to interest 
fruit growers and others in individual-tree performance-record work. 
The information gained from these investigational individual-tree 
performance-record data and related observations made while secur- 
ing them have been the basis upon which have been developed the 
present commercial methods of practice in California in securing 
individual- tree records, in the selection of undesirable trees in estab- 
lished orchards for top-working, and in the choice of trees as sources 
of bud wood for propagation. 
The conclusions presented here have not all been derived from a 
study of the performance-record data. Some phases of tree and 
fruit characteristics can not be recorded in figures or reproduced in 
photographs or other illustrations. These indefinable characteristics 
are of importance and usually are perceived only by those who have 
a natural liking for this kind of work. Though the tree records are 
the foundation upon which has been developed the practice of bud 
selection described in these pages, other factors, a knowledge of 
which has been gained from almost daily and continuous contact 
with the trees and fruits, have been taken into consideration. The 
instinct enabling an observer to distinguish one strain of tree or 
fruit from another and to select the best from among many indi- 
viduals studied during the individual- tree performance-record work 
is almost, if not equally, as important as the actual tree records 
themselves. It is an essential and important qualification for any- 
one who expects to make any standardization through bud selection 
in the Washington Navel orange or other fruit variety. This point 
should be emphasized, for although the data secured from the indi- 
vidual-tree records is of the utmost importance from many stand- 
points, one of its most important uses is for the training of .the judg- 
ment of the observer. The knowledge of trees and their fruits 
gained in this systematic manner'f rom continuous and intimate con- 
tact with them becomes in time of genuine value in the study of 
varieties and their variations. 
The differences in the characteristics of the various strains of the 
Washington Navel orange variety are often difficult to describe or 
illustrate. The behavior of some of these strains, as shown in this 
bulletin by means of performance records, descriptions, and photo- 
graphs, is only a part of the story. The real differences of the 
trees and fruits must be seen before they can be fully appreciated 
