RON PP ec Boss 4 RO ag aye Mes oo RY Ne 
mm) 4 &, ta * ae 
+ S ble me ¢ A te 
i it Daf a 
s- ty A 
The Cell as an Individual. Fy pio a. 
Merten pike EE aT ES 
shells corresponds to a complete system consisting of a * 
- number of thickening-layers, and may manifest the striation DA ae 
t 
“ys r 
; v 
Aik 
% 
E : 
Fic. 22.—Entire cell, with parts of Fic. 23.—Two cells from the wood of the hie . 
- contiguous cells, from the endo- Scotch fir in transverse section, each =? FONE 
_ sperm (albumen) of the seed of the with a pore #, widened at its base. * | aS 
vegetable ivory, Phytelephas, By the disappearance of the original oe 
with pore-canals(P P) somewhat cell-wall the two widenings have united i eee 
widened at the base. (x 370.) to form the ‘ border,’ Z; z intercellular mite ees 
space. (X 660.) Bove ess t 
already described. This formation is peculiar to more, fd 
- strongly thickened cells, and can usually be detected only = 
3 | re 
o i 
Fic. 24.—Part of a’ wood-cell rs 
| drom™ the "Scotch ‘fir .,seen.” 2: 
vertically (cf Fig. 27); p a 
open pore ; Zits border, which : rae 
_has the appearance, seen from ee Wes 
above, of a_saucer-shaped Fic. 25.—Lignified parenchyma from xs) 
depression with a_ central the shell of the walnut, with branched Se 
orifice . ( x 660.) pore-canals. (x 660.) aah a; 
by the application of powerful chemical reagents, which 
cause the shell to split up by fissures previously existing into 
, & 
