There is no doubt that the proper plan is, to have the gardens adjoining the country-house; and they should be watered, more particularly, by a river running in front of it, if possible; or else with water drawn from a well by the aid of a wheel or of pumps, or by swipes.[942] The ground should be opened just as the west winds are beginning to prevail; fourteen days after which it should be got ready for autumn, and then before the winter solstice it should have another turning up. It will require eight men to dig a jugerum, manure being mixed with the earth to a depth of three feet: the ground, too, should be divided into plots or beds with raised and rounded edges, each of which should have a path dug round it, by means of which access may be afforded to the gardener and a channel formed for the water needed for irrigation. CHAP. 21.—PLANTS OTHER THAN GRAIN AND SHRUBS. Among the garden plants there are some that recommend themselves by their bulbs, others by the head, others by the stalk, others by the leaf, others by both: some, again, are valued for their seed, others for the outer coat, others for their membranous tissues, others for their cartilaginous substance, others for the firmness of their flesh, and others for the fleshy tunics in which they are enveloped. CHAP. 22.—THE NATURAL HISTORY OF TWENTY DIFFERENT KINDS OF PLANTS WHICH GROW IN GARDENS—THE PROPER METHODS TO BE FOLLOWED IN SOWING THEM RESPECTIVELY. Of some plants the fruits[943] are in the earth, of others both in the earth and out of it, and of others, again, out of the earth solely. Some of them increase as they lie upon the ground, gourds and cucumbers, for instance; the same products will grow also in a hanging position, but they are much heavier even then than any of the fruits that grow upon trees. The cucumber, however, is composed of cartilage and a fleshy substance, while the gourd consists of rind and cartilage: this last is the only vegetable production the outer coat of which becomes of a ligneous nature, when ripe. Radishes, turnips, and rape are hidden in the earth, and so, too, are elecampane,[944] skirrets,[945] and parsnips,[946] though in a different manner. There are some plants, again, to which we shall give the name of “ferulaceous,” anise[947] and mallows, for instance; indeed, we find it stated by some writers that in Arabia[948] the mallow becomes arborescent at the sixth month, so much so, in fact, as to admit of its being used for walking-sticks. We have another instance, again, in the mallow-tree of Mauretania, which is found at Lixus, a city built upon an æstuary there; and at which spot, it is said, were formerly the gardens of the Hesperides, at a distance of two hundred paces from the Ocean, near the shrine of Hercules, more ancient, tradition says, than the temple at Gades. This mallow-tree[949] is twenty feet in height, and of such a thickness that there is not a person in existence who is able with his arms to span its girth.