1904] PEIRCE: THE MONTEREY PINE 453 
on the 1901 segment, 31 galled and 70 normal leaves on the 
1902 segment, and no galled leaves at all on the new growth of 
1903. It may be mere accident, of course, that the one leaf 
which held on from 1900 to 1903 should have been a normal 
one, but this is what one should expect from the nature of 
the case. A healthy leaf, contributing nor- 
mally to the plant which bears it, should be 
retained longer than diseased leaves. 
In fig. 3 is shown a cross-section of the 
youngest part of a branch on which there 
were no galled leaves. The growth at the 
time of collecting had already been consider- 
able. This growth is greater than that on 
a branch which had borne galled leaves, for 
the diameter of this branch is greater than 
the diameter of the whole first season’s 
growth of the branches shown in figs. 2-5, 
1903 
Fic. 3.—No galls. 
1903 1902" 
which were drawn on the same scale. I ae Gee 
wor, . beeve this .to be a general difference, for all 
. the sections I have made are consistent with 
<2 those here figured. And we should expect on 
general principles that the growth of a tree or 
a branch which had been healthy in preceding 
seasons would be greater and better than that 
of diseased trees or branches. : 
FIG. 5.—1901, 148. In figs. g and 5 we have further evidence 
68n. 1903, no galls. to confirm the opinion expressed above, that 
the width of the annual ring, or to put it more generally, the 
growth of the vascular bundle, is proportioned to the growth 
of the leaves borne on the branch. When one realizes that 
these sections are from different branches on the same sides 
of the same trees, that therefore the conditions other than those 
produced by the parasite were similar each season for healthy 
and for galled branches, one is compelled to attribute the 
difference to the effects of insects. 
Taking into account what was said above about the differ- 
ences in area between normal and galled leaves, and also the fact 
1901 
