Injuries inflicted by the hand of man are productive also of bad effects. Thus, for instance, pitch, oil, and grease,[3203] if applied to trees, and young ones more particularly, are highly detrimental. They may be killed, also, by removing a circular piece of the bark from around them, with the exception, indeed, of the cork-tree,[3204] which is rather benefitted than otherwise by the operation; for the bark as it gradually thickens tends to stifle and suffocate the tree: the andrachle,[3205] too, receives no injury from it, if care is taken not to cut the body of the tree. In addition to this, the cherry, the lime, and the vine shed their bark;[3206] not that portion of it, indeed, which is essential to life, and grows next the trunk, but the part that is thrown off, in proportion as the other grows beneath. In some trees the bark is naturally full of fissures, the plane for instance: in the linden it will all but grow again when removed. Hence, in those trees the bark of which admits of cicatrization, a mixture of clay and dung[3207] is employed by way of remedy; and sometimes with success, in case excessive cold or heat does not immediately supervene. In some trees, again, by the adoption of these methods death is only retarded, the robur and the quercus,[3208] for example. The season of the year has also its peculiar influences; thus, if the bark is removed from the fir and the pine, while the sun is passing through Taurus or Gemini, the period of their germination, they will instantly die, while in winter they are able to withstand the injurious effects of it much longer: the same is the case, too, with the holm-oak, the robur, and the quercus. In the trees above mentioned, if it is only a narrow circular strip of bark that is removed, no injurious effects will be perceptible; but in the case of the weaker trees, as well as those which grow in a thin soil, the same operation, if performed even on one side only, will be sure to kill them. The removal of the top,[3209] in the pitch-tree, the cedar, and the cypress is productive of a similar result; for if it is either cut off or destroyed by fire, the tree will not survive: the same is the case, too, if they are bitten by the teeth of animals.
Varro[3210] informs us, too, as we have already stated,[3211] that the olive, if only licked by a she-goat, will be barren.[3212] When thus injured, some trees will die, while in others the fruit becomes deteriorated, the almond,[3213] for instance, the fruit of which changes from sweet to bitter. In other cases, again, the tree is improved[3214] even—such, for instance, as the pear known in Chios as the Phocian pear. We have already mentioned[3215] certain trees, also, that are all the better for having the tops removed. Most trees perish when the trunk is split; but we must except the vine, the apple, the fig, and the pomegranate. Others, again, will die if only a wound is inflicted: the fig, however, as well as all the resinous trees, is proof against such injury. It is far from surprising that, when the roots of a tree are cut, death should be the result; most of them perish, however, when, not all the roots, but only the larger ones, and those which are more essential to life, have been severed.
Trees, too, will kill one another[3216] by their shade, or the density of their foliage, as also by the withdrawal of nourishment. Ivy,[3217] by clinging to a tree, will strangle[3218] it. The mistletoe, too, is far from beneficial, and the cytisus is killed by the plant to which the Greeks have given the name of halimon.[3219] It is the nature of some plants not to kill, but to injure, by the odour they emit, or by the admixture of their juices; such is the influence exercised by the radish and the laurel upon the vine.[3220] For the vine may reasonably be looked upon as possessed of the sense of smell, and affected by odours in a singular degree; hence, when it is near a noxious exhalation, it will turn away and withdraw from it. It was from his observation of this fact that Androcydes borrowed the radish[3221] as his antidote for drunkenness, recommending it to be eaten on such occasions. The vine, too, abhors all coleworts and garden herbs, and the hazel[3222] as well; indeed it will become weak and ailing if they are not removed to a distance from it. Nitre, alum, warm sea-water, and the shells of beans[3223] and fitches act as poisons on the vine.
CHAP. 38. (25.)—PRODIGIES CONNECTED WITH TREES.
Among the maladies which affect the various trees, we may find room for portentous prodigies also. For we find some trees that have never had a leaf upon them; a vine and a pomegranate bearing[3224] fruit adhering to the trunk, and not upon the shoots or branches; a vine, too, that bore grapes but had no leaves; and olives that have lost their leaves while the fruit remained upon the tree. There are some marvels also connected with trees that are owing to accident; an olive that was completely burnt, has been known to revive, and in Bœotia, some fig-trees that had been quite eaten away by locusts budded afresh.[3225] Trees, too, sometimes change their colour, and turn from black to white; this, however, must not always be looked upon as portentous, and more particularly in the case of those which are grown from seed; the white poplar, too, often becomes black. Some persons are of opinion also that the service-tree, if transplanted to a warmer locality, will become barren. But it is a prodigy, no doubt, when sweet fruits become sour, or sour fruits sweet; and when the wild fig becomes changed into the cultivated one, or vice versâ. It is sadly portentous,[3226] too, when the tree becomes deteriorated by the change, the cultivated olive changing into the wild, and the white grape or fig becoming black: such was the case, also, when upon the arrival of Xerxes there, a plane-tree at Laodicea was transformed into an olive. In such narratives as these, the book written in Greek by Aristander abounds, not to enter any further on so extended a subject; and we have in Latin the Commentaries of C. Epidius, in which we find it stated that trees have even been known to speak. In the territory of Cumæ, a tree, and a very ominous presage it was, sank into the earth shortly before the civil wars of Pompeius Magnus began, leaving only a few of the branches protruding from the ground. The Sibylline Books were accordingly consulted, and it was found that a war of extermination was impending, which would be attended with greater carnage the nearer it should approach the city of Rome.
Another kind of prodigy, too, is the springing up of a tree in some extraordinary and unusual place, the head of a statue, for instance, or an altar, or upon another tree even.[3227] A fig-tree shot forth from a laurel at Cyzicus, just before the siege of that city; and so in like manner, at Tralles, a palm issued from the pedestal of the statue of the Dictator Cæsar, at the period of his civil wars. So, too, at Rome, in the Capitol there, in the time of the wars against Perseus, a palm-tree grew from the head of the statue of Jupiter, a presage of impending victory and triumphs. This palm, however, having been destroyed by a tempest, a fig-tree sprang up in the very same place, at the period of the lustration made by the censors M. Messala and C. Cassius,[3228] a time at which, according to Piso, an author of high authority, all sense of shame had been utterly banished. Above all the prodigies, however, that have ever been heard of, we ought to place the one that was seen in our own time, at the period of the fall of the Emperor Nero, in the territory of Marrucinum; a plantation of olives, belonging to Vectius Marcellus, one of the principal members of the Equestrian order, bodily crossed the public highway, while the fields that lay on the opposite side of the road passed over to supply the place which had been thus vacated by the olive-yard.[3229]
CHAP. 39. (26.)—TREATMENT OF THE DISEASES OF TREES.
Having set forth the various maladies by which trees are attacked, it seems only proper to mention the most appropriate remedies as well. Some of these remedies may be applied to all kinds of trees in common, while others, again, are peculiar to some only. The methods that are common to them all, are, baring the roots, or moulding them up, thus admitting the air or keeping it away, as the case may be; giving them water, or depriving them of it, refreshing them with the nutritious juices of manure, and lightening them of their burdens by pruning. The operation, too, of bleeding,[3230] as it were, is performed upon them by withdrawing their juices, and the bark is scraped all round[3231] to improve them. In the vine, the stock branches are sometimes lengthened out, and at other times repressed; the buds too are smoothed, and in a measure polished up, in case the cold weather has made them rough and scaly. These remedies are better suited to some kinds of trees and less so to others: thus the cypress, for instance, has a dislike to water, and manifests an aversion to manure, spading round it, pruning, and, indeed, remedial operations of every kind; nay, what is more, it is killed by irrigation, while, on the other hand, the vine and the pomegranate receive their principal nutriment from it. In the fig, again, the tree is nourished by watering, while the very same thing will make the fruit pine and die: the almond, too, if the ground is spaded about it, will lose its blossom. In the same way, too, there must be no digging about the roots of trees when newly grafted, or indeed until such time as they are sufficiently strong to bear. Many trees require that all superfluous burdens should be pruned away from them, just as we ourselves cut the nails and hair. Old trees are often cut down to the ground, and then shoot up again from one of the suckers; this, however, is not the case with all of them, but only those, the nature of which, as we have already stated,[3232] will admit of it.
CHAP. 40.—METHODS OF IRRIGATION.
Watering is good for trees during the heats of summer, but injurious in winter; the effects of it are of a varied nature in autumn, and depend upon the peculiar nature of the soil. Thus, in Spain for instance, the vintager gathers the grapes while the ground beneath is under water; on the other hand, in most parts of the world, it is absolutely necessary to carry off the autumn rains by draining. It is about the rising of the Dog-star that irrigation is so particularly beneficial; but even then it ought not to be in excess, as the roots are apt to become inebriated, and to receive injury therefrom. Care should be taken, too, to proportion it to the age of the tree, young trees being not so thirsty as older ones; those too which require the most water, are the ones that have been the most used to it. On the other hand, plants which grow in a dry soil, require no more moisture than is absolutely necessary to their existence.