| The Construction of the Plant out of Cells. 
% f Sat 7 
bog > Ae : » 
tissue finally encloses the p/erome or intermediate tissue, 
situated not very deep down and laterally from the apex, 
which breaks up into the procambium and the fundamental 
tessue. ‘The procambium is formed in many plants from.the 
entire outer zone of the plerome, while in others it consists 
3 of only a few groups of 
its cells ; from the fun- 
damental tissue it is 
further distinguished by 
the arrangement and the 
are prosenchymatous, 
while those of the funda- 
mental tissue remain 
parenchymatous. 
The contrast between 
the epedermal tissue and 
ae 
Fic. 83 I1.—Longitudinal section (partly dia- 
grammatic) through the young embryo of the 
shepherd's purse ; Z epidermal tissue ; 7 cor- 
tical tissue ; # fundamental tissue or pith; Fic. 84.—Papilla from the young 
# procambium ; w root-cap; s suspensor. stigma of Lzlzusme bulbiferune. 
_~ (After Hanstein, magnified : see fig. 363.) (x 660.) 
_ the subjacent masses of tissue is the more evident the greater 
the exposure of the part of the plant to air and light, and 1s also 
usually more conspicuous in the permanent parts than in those | 
which are more fugitive. In the lowest plants, Algze, Fungi, 
and Lichens, and even in the stem of Hepatice, the epidermal 
structure consists only in the outer layers of cells having — 
thicker and firmer cell-walls and smaller cavities than the 
t, 
: oF 
form of its cells, which — 
4 
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> hi ee 
am ; f 
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