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 Ericaceae 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 Ärctostaphylos Uva-ursi. To this divi- 

 sion belong also Phyllodoce, Cassiope hypnoides, Loiseleuria, 

 Bhododendron lapponicum, and Vaccinium Vitis-idœa. Ärcto- 

 staphylos alpina belongs also to this group, although it presents 

 certain peculiarities. 



My warm thanks are due to Dr. Rendle of the British 

 Museum for his kindness in reading the proofs of the present 

 paper. 



5—5—1908. 



