XXXIV INTRODUCTION. 



loculicidal, and the valves either bear the placentas or dissepiments along their 

 middle line, or leave them attached to the axis. Sometimes also the capsule 

 discharges its seeds by slits, chinks, or pores, more or less regularly arranged, 

 or bursts irregularly, or separates into two parts by a horizontal line ; in the 

 latter case it is said to be circumsciss. 



the Nut or Achene, which is indehiscent and contains but a single seed. 

 When the pericarp is thin in proportion to the seed it encloses, the whole 

 fruit (or each of its lobes) has the appearance of a single seed, and is so called 

 in popular language. If the pericarp is thin and rather loose, it is often called 

 an Utricle. A Samara is a nut with a wing at its upper end. 



159. Where the carpels of the ovary are distinct (125) they may severally 

 become as many distinct berries, drupes, capsules, or achenes. Separate carpels 



. are usually more or less compressed laterally, with more or less prominent inner 

 and outer edges, called sutures, and, if dehiscent, the carpel usually opens at 

 these sutures. A Follicle is a carpel opening at the inner suture only. In 

 some cases w T here the carpels are united in the ovary they will separate when 

 ripe ; they are then called Cocci if one-seeded. 



160. The peculiar fruits of some of the large Orders have received special 

 names, which will be explained under each Order. Such are the siliqua and 

 silicule of Crucifera?, the legume of Leguminosoe, the pome of Pyrus and its 

 allies, the pepo of Cucurbitacese, the cone of Coniferee, the grain or caryopsis 

 of Grraminese, etc. 



§ 14. The Seed. 



161. The Seed is enclosed in the pericarp in the great majority of flowering 

 plants, called therefore Angiosperms, or angiospermous plants. In Coniferce 

 and a very few allied genera, called Gymnosperms, or gymnospermous plants, 

 the seed is naked, without any real pericarp. These truly gymnospermous plants 

 must not be confounded with Labiatce, Boraginece, etc., which have also been 

 falsely called gymnospermous, their small nuts having the appearance of seeds 



< 158 )- 



162. The seed when ripe contains an embryo or young plant, either filling or 

 nearly filling the cavity, but not attached to the outer skin or the seed, or more 

 or less immersed in a mealy, oily, fleshy, or horn-like substance, called the 

 albumen, or perisperm. The presence or absence of this albumen, that is, the 

 distinction between albuminous and exalbuminous seeds, is one of great impor- 

 tance. The embryo or albumen can often only be found or distinguished when 

 the seed is quite ripe, or sometimes only when it begins to germinate. 



163. The shell of the seed consists usually of two separable coats. The outer 

 coat, called the testa, is usually the principal one, and in most cases the only 

 one attended to in descriptions. It may be hard and crustaceous, woody or 

 bony, or thin and membranous (skin-like), dry, or rarely succulent. It is some- 

 times expanded into ivings, or bears a tuft of hair, cotton, or wool, called a coma. 

 The inner coat is called the tegmen. 



164. The funicle is the stalk by which the seed is attached to the placenta. 

 It is occasionally enlarged into a membranous, pulpy, or fleshy appendage, 

 sometimes spreading over a considerable part of the seed, or nearly enclosing it, 

 called an aril. A strophiole or caruncle is a similar appendage 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 fu- 

 nicle. 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 several parts are very conspicuous, in others they are very diffi- 



