1914] LLOYD—PINUS RADIATA 317 
which had been trimmed I saw a tendency for the fascicles to pro- 
liferate, but it was quite evident that pruning is by no means as 
efficient a factor as water supply. At the same time, we are bound 
to note that precisely where such a supply is abundant, and, in a 
remarkable case shown in fig. 1, where nitrogen in some form must 
have been quite plentiful, the development of verticillate branches 
was arrested. Other cases of absence of whorls were noted at Car- 
mel, but only in gardens, though we know them to occur in nature 
Fic. 1.—Proliferated spur shoots of Pinus radiata: A, the shoot so formed 
Produced fascicles at once from the axils of the fascicled leaves of the spur shoot; 
B, hypertrophied scale leaves produced on the proliferating axis. 
in other species. It is evident, however, that it is not due to less 
favorable soil conditions even here, since Parties (Joc. cit.) notes 
that arrest of whorl development occurred in Abies on moist, rich 
Sitesin Arizona. One may conceive, furthermore, that a very rapid 
and energetic development of a chief shoot, especially in one in 
which the lateral shoots are not even laid down during the earlier 
Part of period of growth, might be held responsible for failure to 
Produce the usually formed lateral shoots. 
