N the forgoing Descriptions, I have already mention’d the Use of the Parts in some particulars. I shall now a little further explain the manner of their service, both to the Fruit, and to the Seed.
2. §. And first, the Vessels serve for the Figuration of the Fruit. So in an Apple, the Ten great and utmost Branches serve not only to nourish and feed it; but also, by the Arched Lines they draw, to direct and govern the Growth thereof into an orbicular Figure. The Dilatation of these Vessels, not being hindred by any Braces or Conjunction with the Interior ones. By the Slenderness of the Aer-Vessels, as in the Root, so here in the Fruit, much promoted. And by their Saline Principle, first begun.
3. §. The Five midlemost and the Five Inmost serve together, to figure the Coar; the former bounding the Outer, the Latter, the Iner Angles. For were they only Five, or were all Ten in the same Circle, they would only make a round Cavity like that of a hollow Pith. Hence it is that Apples, in which some small Threds of the Vessels strike out into the Circumference, are very Uneven with divers Knobs and Ridges. But Plums, Cherries, &c. where the Vessels all terminate at an Equal distance from the Skin, are Even all round about.
4. §. The Bulk of the Fruit dependeth also on the Braces of the Vessels. For in Plums and Cherries, they are more numerous; but in Apples and Pears they are very loose one from another, and so have liberty left them to spread abroad.
5. §. As also on their Size; that is, on the Size of the Aer-Vessels. Which, the less they are themselves, they serve to make a bigger Fruit. As the less they are in any Root, they serve to make it the more ample. For the less they are, the more pliable to the Attraction of the Aer: and in their Growth must make so many more spiral Rings: by both which means, they make the greater Arches. And therefore a Pear is commonly a smaller Fruit than an Apple; a Plum than a Pear; and a Grape, than a Plum; in all which the Aer-Vessels are still greater and greater.
6. §. From the same Cause, it is also most agreeable, That the Fruit should not come before the Leaves or Flower, but last of all. For the Aer-Vessels, as hath been often noted, are not exactly Cylindrick, but tapered; that is, not only the Fibres consisting of divers of these Vessels, but the Vessels themselves, as they ascend into the Trunck, Branches, Leaves, Flower, and Fruit, grow still more and more slender. So that the smallest coming last, and being the most pliable; they are also best accommodated for the Expansion of the Parenchyma into that we call the Fruit.
7. §. It is likewise a proper Question to be asked, How it comes to pass, That some Plants bear a Fruit, and not all? I answer, That as the Size of the Aer-Vessels conduceth to the Bulk of the Fruit, and the Order of its Growth: So the Number of them, to there being, or not being, any Fruit at all. For the Fruit, as we have already defined it, is an Uterus, which grows moyster and softer, as the Seed ripens. The reason therefore, why the Uterus in some Plants, continues moist and soft after the Seed is ripe; and in some, dries up; is, Because in the former, there is a smaller, in the latter, a greater Quantity of the Aer-Vessels in proportion to the other Parts of the Uterus, and so a greater quantity of Aer. Which as in the Pith of most Plants, so here, by degrees excludes the Sap, or rendering it more evaporable, comes in the room of it; and so the Uterus is dryed up: that is, there is no Fruit produced, but only a Seed-Case.
8. §. From the Size, Number, and Position of all the Vessels in Fruits a reason also may be given, for the diversity of their Tasts. Some Instances have before been given; to which I shall add one or two more. So the Rind of an Orange, is bitter; the Pulp, sower. Because the former is furnished with many Lignous Vessels, the Sulphureous or Oyly Tincture whereof, being copiously mixed with the Acid of the Parenchyma, produce that Tast. Whereas the Pulp, which is very sower, is void of all manner of Vessels. But if the Sap-Vessels are either less numerous or less Sulphureous; they give so mild a Tincture to the Parenchyma, as not to produce a bitter, but a sweet or soft Tast; as in Apples, Grapes, Goosberries, &c. And of a Goosberry, it is particularly to be noted, that whereas, in a Limon, the Pulp only is sower, as being void of Vessels: here, on the contrary, the Pulp only is sweet, whereinto all the Vessels strike, and the Rind sower.
9. §. The diversities of the Skin it self, have their Use. And therefore, the more tender and delicate the Fruit is; the Skin, on the contrary, is thicker and more tough. So Apples have a thicker Skin, than Pears; Plums, than Apples; and Grapes than Plums; those having as it were, only a Coat of Kid, but this of good thick Buff. And therefore some Fruits, although tender, yet either not having so rich a Juyce, or coming early, and so not being exposed to excessive heats, have a very thin Skin, as Mulberries, Strawberries, &c.