71 
also be placed among the species which bear solitary flowers, 
but with some interesting variations. As in V. Myrtillus the 
apex of the shoot fails to develop, and the upper dwarf-shoots 
usurp its place. Each dwarf-shoot usually bears only one or 
two flowers which are protected by scale-leaves, but as is the 
case with the apices of the long-shoots, those of the dwarf- 
shoots also fail to develop. This species is consequently 3-axial. 
False dichotomy is common on account of the shoot structure, 
In a great number of other Ericaceæ the vegetative shoots 
are likewise terminated by floral shoots, but these species are 
bi-axial. New shoots are developed immediately below the 
dying apices of the floral shoots, and are stronger the nearer 
they occur to the latter. The buds which occur lower down 
on the mother-shoot often become dormant. If many new 
shoots are developed it results in a dichotomy with several 
branches often arranged almost in a whorl, e. g. in Ledum; if 
only one or a few new lateral shoots are developed a sympodium 
is often formed, e.g. in Arctostaphylos Uva-ursi. To this divi- 
sion belong also Phyllodoce, Cassiope hypnoides, Loiseleuria, 
Rhododendron lapponicum, and Vaccinium Vitis-idea. Arcto- 
staphylos alpina belongs also to this group, although it presents 
certain peculiarities. 
My warm thanks are due to Dr. Reypre of the British 
Museum for his kindness in reading the proofs of the present 
paper. 
3—59— 1908. 
