378 BOTANICAL GAZETTE [MAY 
P. parviflora, I found numerous examples of similar proliferations. 
A large proportion of these branches formed in this way perish 
later, but some persist and develop normally. Sometimes in these 
species the spurs which will proliferate have an extra needle. In 
P. silvestris this is normally the case. In vigorous specimens the 
lower branches on the swollen branch node of this form come 
regularly from trifoliar spurs. Many of these branches persist, 
and I have also observed that sometimes the main axis comes from 
a spur, no special terminal bud 
being formed. This condition, 
however, is rare in the Scotch 
pine at the stage (about 8 years 
old) examined. In P. Banksiana 
in the same plantation prolifera- 
tion was not so common as in the 
other two species? but occurred 
under the same conditions. 
In some young plants of P. 
ponderosa var. Jeffreyi, 1 have 
found proliferation very common. 
These plants were about 6 years 
of age, and did not exhibit any 
special vigor of growth. Text 
pone 
Fic. 1.—Pinus ponderosa var. Jef- 
(one-half nat. size): the main 
branch developed from 
spur shoots in a plant about 6 years 
old. P 
freyi 
axis 
fig. 1 shows the main axis and a 
branch, with some of the needles 
of the spur from which they arose 
attached to their basal regions. 
Others of these needles have be- 
come detached. In these plants 
there are normally only 3 needles to a spur. In the axial stem 
producing spur shown above, 4 needles are still attached to si 
base, and the broken stumps of 2 others can be clearly seen. The 
branch spur has but 2 needles intact, but the stumps of 2 oF 3 
* ui. . . Norfolk 
? Mr. C. H. Morse, while on a visit to the government nurseries In 
he same 
8 years of age, and fairly common in P. Banksiana and P. Strobus of about t 
age.” 
