78 
COURSE OF THE SAP. 
[Part II. 
Diminution in 
the size of the 
pith and its 
disappearance 
vulgar errors. 
This may be seen to be so in Plate I. page 232.; 
and also, if you divide an end-bud of a horse- 
chestnut branch, or if you divide the branch at 
any of the joints, where one year’s growth ends, 
and the next begins. The channel of the pith 
may be seen to be continuous through the head 
of each annual cone; of the same size as the 
upper part of the older growth, and considerably 
smaller than the lower part of the newer growth. 
The pith, in fact, tapers upwards precisely as 
the shoot does; and the pith of the new year’s 
shoot, notwithstanding its communication with 
the taper top of the pith of the last year’s shoot, 
stands with as broad a basis as that of the seed¬ 
ling. I think that this junction of the taper 
top of the pith of one year’s shoot, with the 
broad base of the pith of the next year’s shoot, 
is the origin of the ideas that the pith of each 
shoot becomes annually smaller than that of the 
shoot above it, by the new annual pressure from 
without of the wood, and that the pith even¬ 
tually disappears. Both these ideas are vulgar 
errors. Dr. Lindley believes (or did, in 1849) 
of the pith, that, “ its office of nourishing the 
young parts being accomplished, it is of no 
farther importance, and dies.” This may be so, 
certainly, but I wonder what the Doctor’s reasons 
