STEMS AND SHOOTS. 
85 
between it and the bark; while the pith is squeezed 
smaller and smaller in the centre. In such a tree 
we find the lower 
and older part of the 
trunk thicker than 
the higher and 
younger part. 
8. But in the 
stem of the palm- 
tree, fresh wood 
grows in long thread 
like bundles which do 
not join together to 
form rings. The pith 
does not run like a cord through the centre of 
the stem, as in the mango, but is mixed up with 
the long threads of wood, that 
grow side by side though apart 
from each other. As they 
grow, they force the older 
wood-threads outwards, press- 
ing them so close that the 
outer part of the wood be- 
comes very hard. 
9c " In trees that grow in 
size in the same way as the palm, then, the wood 
is hardest near the outside. But in the mango, 
logwood, and other trees that grow by adding 
i 
Q'runk of Tree cut across, showing the Rings. 
Piece of Palm Stem cut 
downwards and crosswise and 
showing the cut ends of the 
woody fibres. 
