OUTLINES OF BOTANY. LXV 
may thus be ae from the granules 
chromule, a name given to a ee colouring matter when not green. 
wax, oils, camphor, and resinous matter, are common in cells or in 
cavities in the tissues between the cells, also various mineral substances, 
either in an haa ean 8 state or as microscopic crystals, when they are 
called Raphide 
§ 2. Arrangement of the Elementary Tissues, or Structure of the Organs 
of Plants. 
3. Leaves, young stems, and branches, and most parts of phaeno- 
gamous plants, during the first year of their existence consist anatomi- 
cally of 
(1) a etal 304 or ir oigpeaing mass of cellular tissue, which is 
developed both vertically as the stem or other parts increase in length, 
and hoeinontaite ta ein, as yee increase in thickness or breadth. It 
surrounds or is intermixed with the fibro-vascular Spi or it may exist 
alone in some parts of phaenogamous plants, as well as i cry ptogamous 
bro-vascular system, or continuous mass of woody and vascular 
tissue, which is gradually introduced vertically into, and serves to bind 
ther, the cellular pa It is continued from the stem into the 
i h 
a t. 
epidermis, or outer skin, formed of one or more layers of flat- 
rate Pict iare firmly coherent, and usually empty cells, ‘vith either 
thin and transparent or thick and opaque walls. It covers almost all 
r t fro: 
= immediate acti but is wanting in those parts of aquatic plants 
i are constantly inna, 
. The epidermis is ahgpianye pierced by minute spaces between the 
cls, ‘called Siggy, oo They are oval or mouth-shaped, bordered by lips, 
med of t more alia. pea so disposed as to cause the stomate 
lose up in a tate 
hen a 9 
growth, the anatomical structure of its stem or other perennial parts 
ec complicate 
with 
ry few excepti the bi classes Dicotyledons and Monocotyledons 
(162), foun ten Hin iy structure of the embryo. In iain (Dicotyledons) 
the woody system is slack 4 in concentric layers between a central pit 
(198, 1), and an external separable bark (198, 5). In Endogens ahseee 
cotyledons) the woody system is in separate small bundles or fibres run- 
ning through the cellular system without apparent Tessier an ere is 
sti para 
196. The anatomical structure is also somewhat sp sei in the — 
organs of plants. In the Root, althoug bes it is constructed generally 
the same plan as the stem, _— the oe organization, and the differcaise 
between Exogens and Endogens, is often disguised or obliterated oe irre- 
Hillebrand, Flora of the ie Islands. 
