Fig. 6. which is the root of the white saxifrage (Saxifraga granulata).

Fig. 6.

The didymous, or twin root (RADIX didyma), is. when two tubers grow together, as in many of the orchis tribe, Fig. 7. (a); and in many species of the same family the tubers split into finger-like divisions, forming the palmated root (RADIX palmata), Fig. 7. (b)

9. RADIX bulbosa, the bulbous root, which we shall now consider, appertains to many plants, and assumes several varieties in shape and structure. It is usually described as being solid, or tunicated, or scaly. We have an example of the solid bulb in

crocus, Fig. 8. (a), and in this plant we find a small bulb standing immediately over a larger, forming a BULBUS duplicatus, or duplicated bulb, or in other words, a RADIX duplicata, duplicated root.

In some plants, that part which is between the stem and the root, and which bears the name of intermediate stem, swells into a bulbous form, and is not unfrequently described as a real bulb; the turnip is an instance, but it is a gross mistake to consider the turnip as a bulb, though it is not unfrequently cited, and figured, as such.

We often find, on cutting a bulbous root across, that it is not solid, but composed of many concentric layers, or coats; this forms the tunicated bulb, as in the onion, Fig. 8. (b)

In other instances the bulb is composed of many scales or squamæ, forming the scaly bulb (BULBUS squamosus), of which the lily affords a familiar example, Fig. 8. (c)

garlic. This is named a compound bulb (BULBUS compositus), and sometimes a nestling root (RADIX nidularis); but the former appellation seems more proper.

Having adverted to these different kinds of bulbous roots, I must observe that the bulb is not really the part which performs the true office of a root. We have already seen that the radiculæ, or fibrous ramifications, are the essential organs for conveying nutriment to the plant. Now, we do not find bulbs sending out such fibres; but the base of the bulb is a solid stratum or plate, and from it many threads shoot down into the soil; and these are to be regarded as the real roots. This plate is represented at Fig. 9. (a)

Fig. 9.

b

Bulbs, indeed, are altogether analogous to the buds of trees, and in some plants they are, like the latter, produced upon the stems or branches, as in several of the lily tribe, the bulbiferous coral-wort (Dentaria bulbifera), the magical onion, garlic, &c.

In general, bulbs which bear flowers, die after. that operation is over; but the plant is often continued, exclusively of its propagation by seeds, by the formation of new bulbs, which shoot out from the base or sides of the original bulb, and grow into new plants, after the latter has perished. See Fig. 9. (b) We may particularly observe this mode

ECONOMICAL USES OF BULBS.

17

of propagation in the tubers of the orchis tribe, which are usually two in number, and which, by the bye, Linnæus names bulbs. Of these tubers, one belongs to the plant of the present year; the other to that of next year; which again shoots out a tuber at its side for the third year, and so on. In this way such plants change their situation; the flower of every successive year becoming further removed from the place of the original one.

With respect to the economical uses of bulbous roots, many of them are profitable as food or medicines. In Africa, the bulbs of several species of Ixia are used as articles of diet; and in some places, those of the Star of Bethlehem, especially of the broad-leaved species, are much consumed by the lower classes. The roots of the tulip are converted to a similar purpose in some parts of Italy; but perhaps no people derive so much advantage from bulbous roots as the Kamtschatkans do from the Kamtschatka lily (Lilium Camschatcense), called saranne in their language. At the period of its flowering, the whole ground is covered with its blossoms. The roots are dried in the sun, and preserved for use; and when baked, they are ground into flour, of which the best bread of these people is made. They are used also as we do potatoes.*

You have not perhaps before heard of the economical uses of the bulbs now mentioned; let me, therefore, beg your attention a little to some with

which you are well acquainted. I allude to the onion, leek, and garlic.

The name of the onion in Latin was cepa, which was. taken from caput the head, on account of the shape of the bulb. The English word onion is said to be derived from the Latin unio, which means the number one, because this plant sends off no offsets or bulbs from the original, for no one ever saw two onions at one stalk. This vegetable is cultivated over most of the known world, but its original country is unknown. It is most probable that Egypt was its native place; we know at least, that it was used there as food more than two thousand years before the birth of Christ, as it was one of the things the want of which the Israelites deplored after their departure from that kingdom. We find in the eleventh chapter of Numbers these words: "And the children of Israel also wept again, and said, Who shall give us flesh to eat? We remember the fish which we did eat in Egypt freely; the cucumbers, and the melons, and the leeks, and the onions, and the garlic."

Now in this country the loss of the latter articles would not be considered as a very grievous privation; but the onion we are accustomed to, is very different from that of Egypt, which, by the uncontradicted testimony of travellers, is delicious. "Whoever," Hasselquist says, "has tasted onions in Egypt, must allow that none can be had better