xx INTRODUCTION TO BOTANY. 
the samara or key-frwit, a nut or akene, having a broad wing at 
apex or margin (as in the Ash). 
All the above are indehiscent. 
The principal dehiscent dry fruits are, 
the follicle, a pod tormed of a single free carpel, dehiscent, along its 
ventral or seed-bearing suture only (as in the Larkspur, the 
Asclepiadee, etc). 
the capsule, a pod or dehiscent fruit of any compound pistil, whether 
formed from an inferior or a superior ovary. The pyzis, or 
pyxidium, is only a capsule which opens by a circular, horizontal, 
nearly medial line, cutting off the upper half like a lid. 
136. Peculiar names given to the fruit or parts of the fruit in Crucifere, 
Leguminosae, Rosacea, Cucurbitacee, Umbellifere, and some other large 
Orders, will be explained under those Orders. 
137. The dehiscence of a capsule is said to be septicidal, when the carpels 
separate at the line of junction; in this case the placentze are either 
marginal, or attached to the more or less inflexed margins, constituting 
the dissepiments. The dehiscence is locu/icidal, when the margins of the 
carpels remain joined, while the dorsal sutures split open; in this case the 
placentze or dissepiments will be borne in the middle of the valve. Septi- 
fragal dehiscence, in which the valves fall away, leaving persistent dis- 
sepiments or axile placentze, may occur either in septicidal or loculicidal 
capsules. Circular, horizontal dehiscence (as in a pyais) is called cirewm- 
scissile. When in a fruit, consisting of one-seeded carpels, the carpels fall 
away either closed or nearly closing round the seed, each segregated 
carpel is called a coccus. 
§ 16. The Seed. 
188. A seed is the fertilized ovule arrived at maturity. It is almost 
always, except in Conifers, enclosed in the pericarp. It contains, when 
ripe, an embryo or young plant, either filling or nearly filling the cavity, 
but not attached to the outer shell or skin of the seed; or immersed in, or 
lying close to, a mealy, horny, oily, or fleshy substance, called the albumen 
or perisperm. 'The presence or absence of this albumen, that is, the dis- 
tinction between albwminous and exalbwminous seeds, is one of great im- 
portance. The embryo or albumen can often only be found or distin- 
guished when the seed is quite ripe, or sometimes only when it begins to 
germinate. 
139. The shell of the seed consists usually of two separable coats. The 
outer coat, called testa, is usually the principal one, and in most cases the 
only one attended to in descriptions. It may be hard and crustaceous, or 
thin and membranous, or thin and chartaceous or papyraceous (like parch- 
ment or paper), or rarely succulent. It is sometimes expanded into wings, 
or bears a tuft of hair, cotton, or wool, called a coma. 'The inner coat is 
called tegmen. 
140. The funicle (115) or stalk by which a seed is attached to the 
placenta, is occasionally enlarged into a membranous, pulpy, or fleshy ap- 
pendage, which sometimes almost closes over the seed; this is called an 
aril. A strophiole or caruncle is a similar appendage, originating in the 
testa. Seeds having an aril are said to be aridlate. 
141. The Aidwm (115) is the scar left on the seed when it separates from 
the funicle. The micropyle (118) is the mark indicating the position of the 
foramen of the ovule. 
142. The Embryo consists of the radicle or root-stem; one or two coty- 
ledons or primary leaves (seed-leaves) ; and the plumule, or first leaf-bud 
of the young plant. In many seeds, especially when there is no albumen, 
these several parts are very conspicuous; in others they are difficult to dis- 
