OF BUDS. 



37 



ns in tlie common onion, cut 17,/i and the hya- 

 cinth. They are then named coated or tunicated 

 bulhs. At other times, these scales are smaller, free 

 at their sides, and cover each other only in the 

 manner of tiles on a roof; as in the white lily, cut 

 1 7,.<7. Lastly, the coats are sometimes so close as to 

 be confounded together, when the bulb seems as 

 if formed of a solid and homogeneous substance. 

 Bulbs of this kind are named solid, as in the 

 common saffron. 



Bulbs are generally of an oval or globular 

 fonn. Sometimes, however, they are more or 

 less elongated and even cylindrical ; as is ob- 

 served in some species of Allium. In the ba- 

 nanas the bulb is very elongated, cylindrical, and 

 stem-like. They are sometimes simple, or fonned 

 of a single body ; as in the tulip and squill. Or 

 they are multiple, when several small bulbs are 

 found collected under the same envelope; as 

 in garlic. 



Bulbs, being the buds of certain perennial 

 lierbaceous plants, are necessarily reproduced 

 every year. But their regeneration does not 

 take place in the same manner in all the species. 

 Sometimes the new bulbs arise in the very centre 

 of the old ones, as in the common onion ; at 

 other times, from the lateral part of their sub- 

 stance, as in meadow saffron ; or the newbullis are 

 developed by the side of the old ones, as in the 

 tulip and hyacinth; orabove them, as in ^/o<;?20&«y 

 or beneath them,- as in many species of ixia. 

 In common language, the young bulbs are named 

 ojfsets. 



In proportion as a bulb shoots up the stem 

 which it contains, the outer scales diminish in 

 thickness, fade, and at length become perfectly 

 dry. They consequently appear to supply the 

 young stem with a portion of the materials ne- 

 cessary for its development. 



Tubercles are tnie subterranean bulbs, belong- 

 ing to certain perennial plants. They are some- 

 times simple, and develope only a single stem ; 

 as in the genus orcliis. Occasionally multiple, 

 that is, several together, each sending out a par- 

 ticular stem ; as in saxifraga granulata. Some- 

 times compound, which is the case when several 

 stems issue from a single tubercle ; as in the potato. 



The name of bulbils is applied to a kind of 

 small solid or scaly buds, that grow on different 

 parts of a plant, and are susceptible of vegeta- 

 ting by themselves; or which, when detached 

 from the parent plant, become developed and 

 produce a vegetable perfectly similar to that 

 whence they derived their origin. Plants bear- 

 ing buds of this kind are named viviparous. 

 They may occur in the axiUa of the leaves. 

 At other times they are produced in the place 

 of the flowers. The nature of the bulbils is 

 similar to that of the bulbs properly so called. 

 Sometimes they are scaly; at others solid and 

 compact. 



The small bodies developed in different parta 

 of agamic plants, such as ferns, lycopodiacese, 

 mosses, lichens, &c., and which have been im- 

 properly named seeds, must be considered as tnie 

 bulbils. Although these bodies, to which we 

 give the name of sporules, are capable of pro- 

 ducing a plant similar to that fi-om which they 

 are detached, they cannot bo confounded with 

 true seeds. In fact, the essential character of 

 the seed is that it contains an embryo, that is, 

 a body complex in its nature, composed of a 

 radicle or rudiment of a root, a gemmule orgemi 

 of the stem, and a cotyledonary body. By the 

 act of germination, the embryo properly so called, 

 merely developes the parts wliich already existed 

 in it perfectly fonned. Germination does not 

 give rise to them ; it merely places them in cir- 

 cumstances favourable to their growth. In the 

 bulbils, on the contrary, and especially in the 

 spoiTiles of the agamic plants, there is no em- 

 bryo. In them there is no trace of radicle, coty- 

 ledons, or gemmule. Germination creates these 

 parts in them. They are not, therefore, true 

 seeds. 



Uses of Bxids and Bulbs. Several kinds of 

 buds are employed in domestic economy as food : 

 such as the turios of asparagus, and of several other 

 plants of the same family. Every one knows 

 the daily use that is made of different species of 

 the genus allium; such as the common onion, 

 the garlic, the leek, and the shallot. 



The bulbs or buds of some vegetables are also 

 used in medicine. Thus it is of the buds of the 

 ptnus picea infused in beer that spruce beer is 

 made. The scales of the bulb of the common 

 squill furnish a powerful diuretic, and they a,re 

 also employed as a stimulant to the pulmonary 

 organs. Garlic is well kno^vn to be a cure for 

 intestinal worms. 



CHAP. IX. 



THE LEAVES. 



The leaves are the next organs to be con- 

 sidered. They are found on all the higher ordei-s 

 of plants, although many of the simpler kinds 

 are entirely destitute of them. Before ex- 

 panding into their full size, leaves are at first 

 coiled up in a bud, as has been already explained. 

 The manner in which leaves are thus coiled up, 

 differs in the different kinds of plants. Sometimes 

 they arc folded up lengthwise into two halves, 

 so that the margins of each side exactly coincide. 

 Sometimes they are folded fi-om above downwards, 

 as in the aconite ; at other times they are plaited 

 like a fern, as in the common currant and vine, 

 or rolled up in a spiral form, as in the apricot; 

 the margin of the leaves being either rolled 



