Aristotle · a new plain-English translation from the original language
1| [section 1] LIFE is found in animals and in plants. But in animals it is manifest and evident, while in plants it is hidden and not apparent. To establish it, then, a great deal of inquiry must necessarily come first. For the question stands open whether or not plants have soul, and a capacity for desire, pain, pleasure, and discrimination. [section 2] Anaxagoras and Empedocles say that plants are moved by desire, and they affirm that plants perceive and feel pain and pleasure. Of these, Anaxagoras said that plants are even animals, and feel pleasure and pain, taking this as shown by the shedding of leaves and by growth, while Empedocles held that in them the sexes are commingled. [section 3]
2| Likewise Plato too said that plants desire only, on account of the strong compulsion of the nutritive capacity. If this should be established, it will be consistent that they also really feel pleasure and pain and perceive. And if this is established along with their desiring, it will be consistent even though they are always recovered by sleep and roused by wakings. [section 4] Likewise, if we should inquire whether they have breath and a kind proceeding from mixture, or the contrary, we would create much doubt about this and a long inquiry. It is fitting to pass over such questions and not to spend time on researches into particulars that are not easily disposed of. [section 5] Those who said that plants have souls did so because they observed that plants are generated, are nourished and grow, become young and put forth green shoots, and are dissolved by old age, since nothing without soul has these things in common with plants. And because plants have these characteristics, they believed likewise that plants are also held fast by desire. But let us follow first the things that are evident, and then the things that are hidden. [section 6] We say, then, that if a thing is nourished, it already also desires, and it takes pleasure in satiety, but feels pain when it hungers; and these states do not occur except along with perception. Hence the aim of this man wanders in a way that is remarkable, yet not contemptible, since he supposed that plants both perceive and desire.
3| [section 7] Anaxagoras, Democritus, and Empedocles said that plants have both intellect and knowledge. We, rejecting such views as worthless, take our stand on the sound account. We say, then, that plants have neither appetite nor perception. For appetite does not exist except from perception, and the end of our will turns back toward perception. [section 8] We do not find, then, in such things perception, nor a limb that perceives, nor any likeness of one, nor a distinct form, nor anything consequent on this, nor local motion, nor a path toward some object of perception, nor any sign by which we might judge these things to have perception, of the kind by which we know that they are nourished and grow. [section 9] Nor is this established on our part except because we understand the nutritive and growth-capacities to be parts of the soul. Whenever, then, we find such a plant having some part of soul of this kind in itself, we necessarily understand it also to have a soul; but when it is deprived of perception, it is not proper to conclude that it must therefore be incapable of perception — for perception is a cause of the illumination of life.
4| [section 10] The nutritive capacity is a cause of the growth of some living thing. These distinctions arise at this point, because it is hard to grasp, within the same subject, some mean between life and its privation. Someone might say that, since the plant is alive, we should therefore already call it also an animal. Not at all. [section 11] For it is hard to understand how to assign the governance of the plant to the governance of the soul of the animal. For the reason we deny that plants are alive in this sense is that they do not perceive. And indeed there are also some animals deprived of knowledge. [section 12] Since nature, in destroying the life of the animal in death, again preserves this same life within its own kind through generation, it is altogether inconsistent for us to posit some further mean between the ensouled and the unensouled. But we know that shellfish, too, are animals deprived of knowledge, because they are at once plants and animals. [section 13] Perception alone, then, is the cause by which these things are called animals. For genera give names and definitions to their proper species, and species give names to their proper individuals. And the genus must derive from one common cause present in the many, and not from many causes.
5| [section 14] The account of the cause by which the genus is established is not known to just anyone. Again, there are animals deprived of the female sex, others that do not reproduce, others that have no motion; and there are others of different colors, and some that produce offspring unlike themselves, and others that grow up out of the earth or out of trees. [section 15] What, then, is the principle in the soul of the animal? What else could it be but the noble living being that travels around the heaven — the sun, the stars, and the planets — things set apart from the perplexity bound up in these lower things, and which are indeed also unaffected? For perception is an affection of the things that perceive. [section 16] We should also recognize that plants do not have motion from themselves; for they are fixed in the earth, and the earth is unmoved. Let us reason out, then, from where life could come to it, so that we might make it too capable of perception. For these things do not share one common feature. We say that the common cause of the life of animals is perception. This is what produces the distinction between life and death. [section 17] But since the heaven has a governance nobler and more worthy than our own governance, it has been set apart from these things. It is necessary, then, that the perfect animal and the deficient one have something in common; and this is the aim of life. By the privation of this, then, everyone must withdraw from applying such names, because there is no mean.
6| [section 18] Life is a mean; for the unensouled has no soul, nor any part of one. The plant is not among the things deprived of soul, because in it there is some part of soul; but it is not an animal, because there is no perception in it either. It passes gradually out of life into non-life, as do particular things generally. [section 19] We can also put it differently: that the plant is ensouled, and we do not say it is unensouled. But if it has soul, we do not thereby say that it already has some perception too. For a thing that is nourished does not exist without soul. And every animal has soul. But the plant is an incomplete thing. Again, the animal has distinct limbs, the plant indistinct ones. [section 20] It has matter proper to motion, which it has within itself. Again, we can say that plants have soul, because soul is what generates motions within them. But appetite, and motion from place to place, exist only in accordance with perception. Again, drawing in nourishment comes from a natural principle, and this very thing is what is common to animal and plant.
7| [section 21] There will be no concern at all here for perception in the drawing in of nourishment, because everything that is nourished needs, in its proper nourishment, two qualities — I mean heat and cold; and for this reason it needs nourishment that is moist as well as dry; and heat and cold are found in foods both dry and moist. [section 22] None of these natures is separated from what shares in it. For this reason, too, nourishment was from the first made continuous with the thing nourished, right up to the very hour of its destruction; and both animal and plant must make use of it in the way appropriate to each of them. [section 1] Let us investigate, then, this point too, which came before it in our discussion — concerning the appetite of the plant, its motion, and its own soul, and whether anything is given off from the plant itself, so far as breath is concerned. For Anaxagoras said that plants also have breath. But how could this be, when we find many animals that have no breath, and again we find precisely that plants neither sleep nor wake? [section 2] For waking is nothing but a disposition of perception, and sleeping nothing but a weakness of it; and neither of these is found in a thing that is nourished at all hours according to a single governance, but does not perceive in its own nature.
8| [section 3] For when the animal is nourished, what happens? A vapor rises from the food up to its head, and from this it altogether falls asleep; and when the vapor that rises to the head is used up, then it wakes. In some animals this vapor is abundant, and so they sleep little for a time. [section 4] Drowsiness is a checking of motion, and this checking is, in turn, the rest of a thing in motion. But what most of all, and properly, must be investigated in this science is what Empedocles said — namely, whether there is found in plants a female sex and a male sex, and whether there is a form blended from these two sexes. [section 5] We say, then, that the male, when it generates, generates into something else, and the two are separated from one another. [section 6] Since, then, it is found in plants that plants have a male sex and a female sex, and that in every case the male is rougher, harder, and more bristling, while the female is weaker and bears more fruit, we must again inquire whether these two sexes are found blended together at once in plants, as Empedocles said,
9| [section 7] But I do not suppose the matter stands this way. For things that are blended must first be simple in themselves, and the male must exist in its own right and the female in its own right, and only from there be mixed together. But there will be no blending except through the proper generation belonging to each. [section 8] Now it has been found that in plants a blending exists prior to the blending we are discussing, one which must be both the active and the passive cause at one and the same time; but a union of maleness and femaleness is not found joined together in any one plant. If this were so, the plant would perhaps be more complete than the animal. [section 9] And how could this be, given that the animal needs nothing external for its own generation, while the plant needs the seasons of the year for this? For it needs the sun and good temperature and, still more, the air; and it needs these things most of all at the season of its sprouting. [section 10] There is also one principle of the plant's nourishment, from the earth, and again a different principle of its generation, from the sun. Anaxagoras too said that the moisture of plants comes from the earth, and for this reason he said to Lechineus that the earth is the mother of plants, and the sun their father.
10| [section 11] But we ought to set out the blending of the male and female in plants not in this way but in some other manner — namely, that the seed of the plant is like the pregnancy of an animal, which is a mixture of male and female. [section 12] And just as in eggs, when a chick comes to be, its nourishment too comes from there, right up to the very time of its completion and its own emergence, and then the female brings the chick forth at a single moment — so too with the seed of the plant. [section 13] Empedocles, again, said that although plants do not beget offspring in the way animals do offspring, because what is begotten is begotten only from the nature of the seed, and what remains of it at the outset becomes nourishment for the root, and the thing begotten moves itself at once by itself — nevertheless we ought to suppose the same, even in the mixing of male and female plants, as in the case of animals: that the mixture of plants too occurs under some governance. But in animals, when they mate, the kinds mix, and the powers of the kinds, which were previously separate, mix as well, and from these two there comes forth one single thing; and this does not happen in plants.
11| [section 14] For it is not the case that, when the kinds mix, their powers afterward become separate again. If indeed nature mixed the male with the female, it did well to proceed thus, because we find no activity in plants beyond the production of fruit. [section 15] For there is no animal separated from the female except at the seasons when they do not mate. This is because of its many activities and its many kinds of knowledge. [section 16] There are some who suppose plants to be complete, and that the delight of their life lies in the two powers they possess — namely, the nourishment fit for feeding them, and the length of their own existence and of the season when their life buds and bears fruit, and their youth turns back toward them, and nothing superfluous arises in them. [section 17] The plant has no need of sleep, for many reasons: because the plant lies fixed in the earth and is bound by it, and has no motion in itself, nor any definite boundary marked off among its own parts, nor does it have perception, nor self-chosen motion, nor a complete soul; rather it has, more properly, a part of a part of soul.
12| [section 18] And the plant was not made except for the sake of the animal, while the animal was not made for the sake of the plant. And again, if someone should say that the plant needs cheap and poor nourishment, and that although it needs such nourishment, it is nevertheless for the most part firm and continuous and not easily corrupted, and that from this it follows that the plant has something better than the animal, and therefore lifeless things must be nobler than ensouled things — [section 19] but the work of the animal is better than every work of the plant. Besides, we find in the animal all the powers that are in the plant, and many others besides, but not the reverse. Empedocles said again that plants have their generation in a world diminished and not complete as regards its fulfillment, and that when this is completed, no animal is generated. [section 20] But this account is discordant, because the world is whole and continuous, and has never at any time ceased to generate animals and plants and every other kind of form. In each species of plant there is a natural heat and moisture, and when this is used up, the plants grow weak and age and waste away and dry out. And some call this destruction, others do not.
13| [section 1] Some plants have some moisture in them, as resin, as gum, as myrrh, as frankincense, and as Arabian gum. Again, some trees have bonds and veins and a hollow and stocks and bark and marrow within. And some consist for the most part of bark. [section 2] And in some the fruit is under the bark, that is, within the bark and the stock. And some parts of the tree are simple, such as the sap found in them and the bonds and the veins; others are composite from these, such as branches and twigs and leaves. And we do not find all of these present in every plant. [section 3] For some plants have both these and other parts as well — twigs, leaves, branches, flowers, and buds, and a bark surrounding the fruit. And just as in animals there are uniform members, so too in plants. [section 4] And each of the parts of the plant is composite, resembling the members of an animal; and the bark of the plant is naturally like the skin of an animal, and the bonds in turn are like the sinews of an animal.
14| [section 5] Likewise too the rest of what is in it. And some of the parts are divided, in a sense, through unlike parts, others through like parts, as for example in the case of clay: for this is divided in one way through earth alone, and in another way through the elements. So too the lung and the flesh are divided in a primary way, and flesh and lung are parts of these; but they are divided in another way through the elements as well. [section 6] Likewise too the roots of plants. Except that a hand is not divided into another hand, nor a root into another root, nor leaves into other leaves. In these roots, then, and in the leaves themselves, is the composition. Again, some fruits are composed of few parts, others of many parts, as in the case of olives. [section 7] For these have bark, flesh, something shell-like, seed, and fruit. Some also have coverings. And all seeds consist of two barks. [section 8] These, then, are the parts of plants that we have mentioned; and the height of the present discussion is to define these parts of plants, their coverings, and their differentiae — which is very difficult, and especially difficult is defining their substance and their color and the season of their persistence and the constrictions that befall them, and the fact that plants have no dispositions of soul, nor any disposition equal to a disposition of soul.
15| [section 9] If, then, we were to set the parts of the soul in correspondence with the parts of the plant, the account would be drawn out at great length, and perhaps we would not even be able to carry it through, since the parts of plants are distinguished by great differences when we enumerate them. For the part of any given thing belongs to its own genus and to its own substance. [section 10] And when some species of plant is generated, it remains in its proper condition, unless it falls away from that proper condition through some temporal weakness and burdensome affliction. Now of the flowers and fruits and leaves found on plants, some are present in every year, while others are not so and do not persist, like the bark, and like some body that falls away from the thing that sheds it for some cause. [section 11] These do not remain on the plant, because parts of it often fall away that are not clearly demarcated, as hairs fall from human beings, and nails. Except that hairs are generated either in the very parts from which they fell, or elsewhere, outside them. And it has already become clear that the parts of the plant are not clearly demarcated, whether they are or not, but only indeterminate.
16| [section 12] But it would be shameful for us to say that certain things, after which the animal grows and is completed along with them, are not parts of it, while things corresponding to leaves and all such things found on the plant are parts, even though such parts of the animal are not clearly demarcated, and even though they fall away little by little, as the antlers of the deer, and the manes of some animals, and the hair of others, which indeed hide themselves during the winter season in holes and burrow under the earth, even though such an affection is similar to the shedding found in plants. [section 13] We ought, then, to speak about the matters we investigated earlier, and to begin enumerating the proper parts of plants and their common parts, and the differences among these. We say, then, that among the parts of plants there is a great difference in respect of abundance and scarcity, in respect of largeness and smallness, in respect of strength and weakness. [section 14] This is because the sap found in large trees is in some of them like milk, as in the fig tree, in some it is like liquid pitch, as the sap that drips from the vine, and in some it is primordial, as in marjoram and in the plant called opigais and in others.
17| [section 15] Again, there is a plant that has dry parts, another that has moist parts, and so on for other such cases. And there is the plant that has parts distinguished from one another, neither alike nor equal. And some plants have parts alike but not equal; some have parts equal but not alike. [section 16] And note too that there is no fixed place assigned in these matters. The differences among plants are well recognized in their own proper parts; and likewise their shapes are recognized from color, from looseness of texture, from density, from roughness, and from all the other attributes that belong to them in respect of equality, of natural growth, of differentiation, of largeness, of smallness. These, then, are of this sort, and they have many differences besides, as we said before. [section 1] Again, of plants, some bear fruit above their own leaves, others below the leaves. And in some the fruit hangs from the plant's own trunk, in others from the root, as with the plants in Egypt called pearl-plants. In some the fruits are in the middle of the plant. And in some the fruits and the leaves and the stalks are not clearly distinguished from one another.
18| [section 2] And in some plants the leaves are alike to one another, in others not. And some have equal branches, others not such. And the parts we have named are present in all trees, undergoing growth and increase — the root, the shoots, the trunks, and the branches; and these are compared to the limbs of human beings that contain all the other limbs. [section 3] And the root mediates between the plant and its nourishment, and we call it not only a root but also the cause of life; for it supplies life to plants. And the trunk is what alone arises from the earth, and it is comparable to the age of a human being; the shoots are what spring up from the root of the tree, while the branches are what grow up above the shoots. [section 4] But these are not found in all plants. And again, of the plants that have branches, some are continuous, others are not, but rather grow anew from year to year. And again there are plants that have neither branches nor leaves, as mushrooms and the like. [section 5] The branches that are generated in trees, and the bark and the trunks and the pith, are generated from nothing other than the sap itself of the trees. And some call this pith found in trees the womb, others the entrails, others the heart. And these, along with the veins and the flesh of the whole tree, are formed from the four elements.
19| [section 6] And often certain parts are found suited to generating leaves and flowers. And some short shoots are suited to generating flowers, as in willows. And some trees generate both flowers and fruits, and all the other things that are generated from seed, and whatever encloses them. [section 7] And again, of plants, some are trees, others are between trees and herbs; and these are called shrubs. And some are herbs, others are vegetables. Nearly all plants, then, fall under names of these sorts. [section 8] Again, there are trees that have a trunk from their own root, and on these many branches are generated, as in figs and olives; some do not. Again there are other plants, as we said, between trees and small herbs, called shrubs, having many branches at their roots, as the plants called chaste-trees and brambles. [section 9] Vegetables are those that have many trunks from a single root and many branches, as rue, cabbages, and the like. And there are also herbs that do not have a trunk from their own root, but bear leaves directly.
20| [section 10] And some are generated and wither within a single year, as wheat and similar things, others do not. But we cannot know all these things except through reasonings and examples and outline descriptions. Again there are herbs that incline to two extremes, as the herb called royal vegetable. [section 11] There are others called at once both herbs and vegetables; and there are certain others which, when first generated, appear in the shape of an ear of grain, but afterward become trees, as the Arabian bentelloi and the plant called sunflower. [section 12] Myrtle, apple, pear, and the rest of the similar trees are included in this genus, of which many branches are also useless, growing up from their roots. And for this reason it is fitting to make further distinctions among these, so that they may serve for example and reasoning; for we ought not to search out definitions in every case. [section 13] Again, of plants, some are domesticated, some are of the garden, and others wild. In this way we call pears and other such kinds of plants wild, because they do not arise from agricultural care. Again, of plants, some produce fruit, others do not, as willows and certain kinds of oaks.
21| [section 14] And some plants produce oil, and some do not. And some produce leaves, and some do not. And some shed their leaves, and some do not. And some grow branches, and some do not. So there is much to say about the difference among plants in size and smallness, in beauty and shapelessness, in the goodness and badness of their fruits. [section 15] Again, wild trees bear fruit more than cultivated ones do, yet the fruits of cultivated trees are better than those of wild ones. And some plants are produced in dry places, some in the sea; and some in rivers, others in the Red Sea; and some are large in some places and small in others. [section 16] And some are produced on the banks of rivers, some in marshes. And of those produced in dry places, some grow in the mountains, some in the plains. And some live in the driest places, as those in the land of the Ethiopians, and there they grow better than they do elsewhere. [section 17] And some live in high places, some in low ones. And some live in wet places, some in dry ones, and some in both, as the willow. So plants vary greatly with the difference of place, and from this one must also come to understand their differences.
22| [section 1] Again, some plants are fixed to the earth and do not like to be separated from it, but some are transplanted to better places. Likewise, some fruits are better in this place than in another. And of some plants the leaves are hard, of some smooth; and of some split, as those of vines and fig trees, of some not; and of others split a great deal, as those of the pine. [section 2] Some plants consist wholly of bark serving as a mediator. And some have joints, as reeds do, and some do not. And some have thorns, as brambles do, and some are without thorns. And some have many branches, as the wild mulberry does, and some do not. [section 3] And some have a further difference, in that shoots grow out from them while from others they do not; and this comes from nothing else but the difference among their roots. Some have a single root, as the squill does; this grows from the ground and advances sparsely, because it spreads out below, and as it proceeds it is further set apart by the sun, for when the sun strikes it, it grows.
23| [section 4] This same plant also draws up its shoots from below. Again, of the juices found in fruits, some are drinkable and some are not; drinkable are those of grapes and pomegranates and many others, undrinkable those of other plants. [section 5] And of some they are oily, as those of the olive, the pine, and the walnut, and of some they are not. And of some sweet and honey-like, as of dates and figs; and of some hot and pungent, as of marjoram and mustard; and of some bitter, as of wormwood and centaury. Again, of fruits some are composite, made up of flesh and seeds and husks, as cucumbers are, and some of juice and seeds, as pomegranates are. [section 6] And some have their rind outside and their flesh inside, and some have the stone inside and the flesh outside. Some are such that the seed and the covering that wraps it come into being at the same time, as with the fruits of dates and almonds; of some this is not so. [section 7] And some fruits are edible, and inedible only by accident; and some fruits are inedible to us but edible to others, as henbane and hellebore are poison to men but food to quails. Again, some fruits are in cases, as the seeds of the bean; some are in a covering and husk like a kind of woven fabric, as is found in wheat and the rest.
24| [section 8] And some are set in flesh, as the fruits of dates are; some are as if in little dwellings, as acorns are; and others are in many little dwellings and husks and shells, as walnuts are. [section 9] And some ripen quickly, as the fruits of the mulberry and the cherry do; some slowly, as all wild fruits do, or most of them. And some plants bring forth leaves and fruits quickly, some slowly; and of these, some hold on through the winter before they ripen. [section 10] And again the colors of the leaves and fruits, and of the woven coverings that lie upon them, so to speak, are very different, for some plants are green throughout their own whole extent, and some incline toward blackness, some toward whiteness, and some toward redness, on account of the heat that sets ablaze the air mingled with that near the ground. [section 11] Again, the shapes of fruits, when they are wild, occupy different positions, for not all fruits are angular, nor do all run along a straight line. [section 1] Again, of aromatic trees, of some the root is aromatic, of some the bark, of some the wood; of others the parts are wholly aromatic, as with balsam. Again, of trees, some are produced from seed, some by themselves.
25| [section 2] And again, some are pulled up by their roots and transplanted, some from the trunk, some from branches, or from seed. And some by themselves extend little by little, and some into the earth. And some are planted into trees, as grafted plants are. Grafting like onto like is the better practice. [section 3] But there is also another kind of correspondence, by which unlike things come together very well, as apples with pears. Among like things, as fig into fig and vine into vine and almond into almond, [section 4] there is also another kind of grafting among other, different kinds, as wormwood into wild wormwood, and cultivated olive into wild olive, and mulberry into many trees. Again, of trees, both wild and cultivated, every plant does not produce seed like the seed from which each of them grew up. [section 5] For some produce better seed, some worse. And from some bad seeds good trees come forth, as those from a small almond and a sour pomegranate. Again, of some trees, if their seed becomes weak, they fail to become good, as pines and date-palms do.
26| [section 6] Good trees do not easily come forth from bad seed, nor bad trees from good seed. But for a good thing to come from a bad one, and the reverse, is often found among animals. Again, a tree whose bark is very hard becomes barren; but if its root is split and a stone is set into the split, it becomes fruitful. [section 7] And among date-palms, if leaves or catkins or bark of the male date-palm are joined together with the leaves of the female, so that they are somehow brought into contact, the fruits ripen quickly, and their falling is also prevented. The male is distinguished from the female in that its leaves sprout first, and they are smaller than those of the female; but also by its fragrance. [section 8] Elsewhere this comes about from one of these causes, or from all of them. And perhaps too, if a wind carries something of the male's fragrance over to the female, the fruits ripen in this way as well, just as when the leaves of the male hang suspended over the female. [section 9] Likewise wild fig trees, spread out into the ground, contribute much to cultivated fig trees. Wild pomegranate blossoms contribute to olives, when they are planted together.
27| [section 1] Again, some plants change, so they say, into another species, as the walnut does when it grows old. They say too that pennyroyal changes into mint, and that wild rue, cut and planted by the sea, may become water-mint. They say too that wheat and flax change into another species. [section 2] And the poisonous plant that grows in Persia, when transplanted into Egypt or Palestine, becomes edible. Likewise the almond and the pomegranate change, through cultivation, from their own inferior condition into something better. [section 3] Now pomegranates improve when pig dung is put in around their roots, and when they are watered with sweet, cold water; almonds improve when pegs are driven into them and much gum is thereby made to run out of them. And many wild plants become garden plants through this kind of technique. [section 4] Place and cultivation contribute a great deal to these things, and even more the season of the year, which planters need above all. Again, most plants are planted in spring, few in winter and autumn, and fewest of all in summer after the rising of the Dog Star. [section 5]
28| Such planting occurs in few places, and never occurs except sparingly, as in Rome at this season. In Egypt, planting occurs only once a year. Again, some plants put out leaves from their own roots, some from their own gum, some from their own wood. [section 6] And some grow close to the ground, some far from it, some in between. And some bear fruit once a year, others many times, but their fruits do not ripen and remain unripe. [section 7] And some trees are fruitful over many years, as fig trees are; others bear fruit in one year, and in the next recover themselves, as olive trees do, putting out many branches, by which they are also covered over. And some plants are more fruitful in old age, while others, on the contrary, bear fruit more in youth, as almonds, pear trees, and black poplars do. [section 8] The difference between wild and garden plants is distinguished by male and female, once each of them has been recognized through the particular marks found in them: that the male is denser, harder, and has more branches, is less moist, and comes to ripeness more quickly, and has leaves and shoots that are different. The female has less of these.
29| [section 9] We must, then, once we have grasped these things, go on to consider how we might come to know the trees in their own right and the genera in their own right. And likewise concerning plants, how we might understand what the ancients said. How? [section 10] If we examine carefully the books they wrote, and are able to search out the marrow of them by a synoptic inquiry, and come to recognize the oily plants and the plants that have only seed, and those that furnish help, and the medicinal ones, and the destructive ones. And likewise the trees along with the plants. [section 11]
30| To learn their causes as well, we ought to inquire into their generation: how some are generated in some places and not in others; further, their plantings and their roots, and the differences of their juices and their odors and their sap and their gum, and the goodness and badness of each, and their durability — how the fruits of some persist while those of others do not, and for what cause some rot quickly and others slowly — and to inquire also into the peculiar properties of plants, and especially of their roots; and how the fruits of some soften while those of others do not; and how some arouse desire, others sleep, and others even destroy, and many other differences; and how the fruits of some produce milk while others do not. B. The tree has three capacities: the first from the genus of earth, the second from the genus of water, the third from the genus of fire. For from earth comes the growth of the plant, from water its solidification, from fire the unification of the plant's solidification. And we see many of these things also in shelled things.