XXII 
OUTLINES OF 
A strophiole or caruncle is a similar appendage proceeding from the testa by the side 
of or near the funicle. 
165. The hilum is the scar left on the seed where it separates from the funicle. 
The micropyle is a mark indicating the position of the foramen of the ovule (133). 
166. The Embryo (162) consists of the Radicle or base of the future root, one or 
two Cotyledons or future seed-leaves, and the Plumule or future bud within the base 
of the cotyledons. In some seeds, especially where there is no albumen, these se- 
veral parts are very conspicuous, in others they arc very difficult to distinguish 
until the seed begins to germinate. Their observation, however, is of the greatest 
importance, for it is chiefly upon the distinction between the embryo with one or 
with two cotyledons that are founded the two great classes of phsenogamous plants, 
Monocotyledons and Dicotyledons. Cotyledons are said to be conduplicate when folded 
once lengthwise ; contortuplicate when variously folded or twisted ; confer ruminate 
when so united that no line of separation can be traced. 
167. Although the embryo lies loose (unattached) within the seed, it is generally 
in some determinate position with respect to the seed or to the whole fruit. This 
position is described by stating the direction of the radicle next to or more or less 
remote from the hilum , or it is said to be superior if pointing towards the summit 
of the fruit, inferior if pointing towards the base of the fruit. 
$ 15. Accessory Organs. 
168. Under this name are included, in many elementary works, various external 
parts of plants which do not appear to act any essential part either in the vegetation 
or reproduction of the plant. They may be classed under four heads : Tendrils and 
Hooks , Thorns and Prickles , Hairs and Glands. 
169. Tendrils ( cirrhi ) are usually abortive petioles, or abortive peduncles, or 
sometimes abortive ends of branches. They are simple or more or less branched, 
flexible, and coil more or less firmly round any objects within their reach, in order 
to support the plant to which they belong. Hooks are similar holdfasts, but of a 
firmer consistence, not branched, and less coiled. 
170. Thorns and Prickles have been fancifully called the weapons of plants. 
A Thorn or Spine is the strongly pointed extremity of a branch, or abortive petiole, 
or abortive peduncle. A Prickle is a sharply pointed excrescence from the epi- 
dermis and is usually produced on a branch, on the petiole or veins of a leaf, or on 
a peduncle, or even pn the calyx or corolla. When the teeth of a leaf or the stipules 
are pungent, they are also called prickles , not thorns. A plant is spinous if it has 
thorns, aculeate if it has prickles. 
171. Hairs, in the general sense, or the indumentum (or clothing) of a plant in- 
clude all those productions of the epidermis which have, by a more or less appro- 
priate comparison, been termed bristles , hairs, down , cotton , or wool. 
172. Hairs are often branched. They are said to be attached by pie centre , if 
parted from the base, and the forks spread along the surface in opposite directions ; 
plumose, if the branches are arranged along a common axis, as in a feather ; stellate, 
if several branches radiate horizontally. These stellate hairs have sometimes their 
rays connected together at the base, forming little flat circular disks attached by 
the centre, and are then called scales, and the surface is said to be scaly or lepidote. 
173. The Epidermis , or outer s kin , of an organ, as to its surface and indumentum, is 
smooth , when without any protuberance whatever. 
glabrous , when without hairs of any kind. 
glabrescent, glabrate , becoming glabrous. 
striate, when marked with parallel longitudinal lines, either slightly raised or 
merely discoloured. 
furrowed ( sulcate ) or ribbed ( costate ) when the parallel lines are more distinctly 
raised. 
rugose, when rinkled or marked with irregular raised or depressed lines. 
umbilicate, when marked with a small round depression. 
umbonate , when bearing a small boss like that of a shield. 
viscous, viscid, or glutinous, when covered with a sticky or clammy exudation. 
scabrous, when rough to the touch. 
