24 FUNCTIONS OF PLANTS. 



99. Fruits are either simple, proceeding from a single flower, as in the 

 poppy, rose, strawberry, apple, &e., or compound, formed out of several 

 flowers, as in the mulberry, the fig, and all the Coniferse. When simple 

 fruits are formed of a single carpellum, they are called follicles, as in the 

 peony ; legumes, as in the pea ; drupes, as in the peach ; akenia, as in the 

 strawberry; cariopsis, as in corn ; or utricles, as in the chenopodium. The 

 capsule is a many-celled dry pericarpium, as in the poppy ; the silique is a 

 pod, consisting of two or four carpella, as in the cabbage tribe, and all the 

 Cruciferaa. The nut or gland is a dry, bony, one-celled fruit, enclosed in an 

 involucrum, cupula, or cup, as in the oak ; the berry is a succulent fruit, 

 the seeds of which lose their adhesion when ripe, and lie loose in the pulp, 

 as in the grape and the gooseberry ; the orange is also a berry separable into 

 an epicarp, or outer skin, and endocarp or central part in which the seeds 

 are fixed, and a sarcocarp or fleshy substance between the epicarp and the 

 endocarp ; the pome consisting of two or more inferior carpella united, as in 

 the apple ; and the pepo is a pulpy fruit in which the seeds are embedded, 

 but their point of attachment never lost, as in the cucumber. Of all these 

 fruits, the most remarkable are the pine-apple, which is a spike of inferior 

 flowers grown together into a fleshy mass; the fig, which is the fleshy hollow 

 dilated apex of a peduncle, in the interior of which the flowers are arranged, 

 each flower containing a one- seeded pericarpium; the cone of the Abietinae 

 is an indurated amentum ; and when reduced in size, and its scales so firmly 

 adhering as almost to resemble a berry, it is called a galbulus, as in Thuja 

 and Juniperus. 



100. The seed is a mature ovulum, and consists of the integument or testa, 

 the albumen or perisperm, and the embryo, which consists of the cotyle- 

 dons, the radicle, the plumula, and the collar or neck. As all ovula are 

 enclosed within an ovarium, and all seeds are matured ovula ; hence there 

 can be no such thing as naked seed, excepting in Coniferae and Cycadese, in 

 which the ovula are destitute of every covering, and exposed naked to the 

 influence of the pollen. In consequence of some ovula rupturing the ovarium 

 in the course of their growth, the seeds become naked, as in Leontice thalic- 

 troides ; while in some, as in Reseda, the ovula are imperfectly protected by 

 the ovarium, and in that case also the seeds are naked. When a seed 

 is separated from the placenta, and the umbilical cord is removed, a scar 

 appears on the point where it was attached, which is called the hilum 

 or umbilicus. It is very distinct in the common bean, and in all the Legu- 

 minosse. The hilum always represents the base of the seed, or that part 

 whence the roots proceed ; and hence it ought to be placed undermost when 

 the seed is committed to the soil. In curved seeds, however, as in the 

 Mignonette, the apex and base are brought together ; and in sowing such 

 seeds they should be laid on their side. There is much to study on the 

 subject of seeds, both with a view to a scientific knowledge of plants and to 

 their culture, and we must therefore recommend the reader to study either 

 Lindley's Outlines of the First Principles of Botany, or his Introduction to 

 Botany, 3rd edit., 1839; the last being by far the most complete work of 

 the kind extant. 



SECT. V. Functions of Plants with reference to Horticulture. 



101. The development of a plant takes place in consequence of the elas- 

 ticity, excitability, and hygroscopicity of its tissue ; and it requires the, 



