Of Vegetation. 3 3 j 
pofes the tender growing fhoot to be diftend- 
ed like foft wax by the expanfion of the 
moifture in the fpongy pith 5 which dilating 
moifture, he with good reafon concludes 
is hindered from returning back, while it 
expands by the fponginefs of the pith? 
without the help of valves. For 'tis very 
probable that the particles of water, which 
immediately adhere to, and are ftrongly 
imbibed into, and attrafted by every fibre 
of the fpongy pith, will fliffer fome degree 
of expanfion before they can be detached 
by the fun's warmth from each attrafting 
fibre, and confequently the mafs of fpongy 
fibres, of which the pith confifts, muft there: 
by be extended. 
And that the pith may be the more fervke- 
able for this purpofe, nature has provided in 
moft flioots aftroag partition at every knot, 
which partitions ferve not only as plinths, or 
abutments for the dilating pith to exert its 
force on, but alfo to prevent the rarified fap’s 
too free retreat from the pith. 
But a dilating fpongy fubftance, by 
equally expanding it felf every way, would 
not produce an oblong (hoot, but rather a 
globofe one, like an Apple 5 to prevent which 
3 inconvenience 
