BUTLER: ALTERNATE BEARING IN THE APPLE 87 
practically the normal mode of development. Developing at the same time as the 
flowers at the base of the floral axis or purse, these eyes become ordinarily during 
the same season, buds crowned by three or four leaves, unless an exuberance of sap 
forces them to grow into leafy shoots. During the second year they develop into 
buds crowned by six to eight leaves, or floral buds and eam into flower clusters 
the third. It is due to the fact that t q wo years to ean flowers 
that we have alternation of PERE in the sschehibeown pome fruits when 
they are in full bearing and consequently growing moderately. The Sais year of 
the development of the purse pears coincides with the site year. 
e infertile year which follows is the second year of the existence of the 
purse eyes which develop that year into flower buds. These latter opening the 
following year give rise to another floriferous year and so on for succeeding years. 
A study of the method of flowering of the apple will show that 
Courtois’s explanation was sound and that it satisfactorily explains 
biennial bearing. 
In our fruit trees we may distinguish two classes of branches: 
1. Branches of the first order, or structural branches; 2. Branches 
of the second order, or fruit branches. 
A structural branch in its first year of growth is called a leader. 
Fruit branches, on the other hand, are of several kinds. In 
the case of the apple we can distinguish: (1) The fruit branch 
(rameau a fruit); (2) The sprig (brindille); (3) The dart (dard); 
(4) The spur* (lambourde). 
A fruit branch is a leader in which the terminal and axillary 
buds in the upper two thirds or thereabouts of its length become 
flower buds during the season of its development (PLATEs I, FIG. 
2,and 2). The flower buds borne laterally on the leader have 
been described as formed axillarly by D’Albretf and by Gourley, 
though they are in reality borne terminally on almost sessile spurs 
(lambourdes). A close study during the first season of the buds 
from which the supposed axillary clusters arise will show that at 
the close of vegetation the buds are subtended by a rosette of 
leaves and are not in the axil of a single leaf. The buds are, there- 
fore, terminal on sessile spurs and not axillary, as by definition 
an axillary bud is a bud borne in the axil of a leaf. Forney is also 
of this opinion for he states that ‘‘it often happens that the eyes 
* The dard and lambourde, which I have distinguished from one another, are 
o-Saxon horticultural pre 
called indiscriminately spurs in the Ang] 
+ D’Albret. La taille des arbres fruitiers, Ed. 4, 7. Paris. 
t Gourley, J. H. Studies in fruit bud formation, New as Agr. Exp. 
Sta. Tech. Bull. 9,17. 1915. 
. 
