Sie 
fl 
Fic. 79.—Transverse section through a mature resin-passage of Abies excelsx; the 
cavity Hg as well as the thin-walled cells HZ are filled with a semi-fluid resin,” 
while the thick-walled compressed cortical cells p still contain small 
. 
a 
’ 
y 5 
f , 5 ie | | i e x ; . ‘ ; re i of a “the 
flower, whatever its structure [or morphological nature] 
which is formed for the secretion of honey or a saccharine 
A De ¢ Pee aes © 
1 ow Fae 
DST at = hy “A 
‘ 
Wenge 
Die 
tay 
"a 
uid. 
starch. (x 800.) 
; All these separations of masses of tissue are essentially different 
from the transformations of the cell-wall previously described ; although 
Fic. 80.—Transverse section of a resin-gland 
from a young birch-twig; @ epidermal cells ; 
6 a subjacent layer of cork ; c collenchyma- 
tous cortical tissue ; 
\ 
d the papillz of the 
gland which have secreted the solid resin e. 
(x 100.) 
‘as yet been but little studied, the overgrowths of wax on 
ate ; eR at 
- -the surface. These occur especially as a delicate bloom, as 
Fa Oe I Re De er eee 
Oh Fond yn Fa a aN eRe 
< ya ee Pale sie) 
Ve i 
fe. ote MoS MOAPON i Rnme cealten uy ogi ny Pe 
4. Structural and Physiological Botany. 
Lat 
ween ay 
. 
‘A 
quantities of 
it happens often enough with 
processes of secretion that cell- 
walls are ruptured by the pres-_ 
sure of the substances stored 
up in them, and are carried 
away along with the waste 
products (see p. 23). 
In this connection — 
should be mentioned also | 
certain structures which 
are certainly of the greatest 
importance for the life of 
the plant, but which have 
shige 
