PLUM consisteth of a Parenchyma, the Two general Kinds of Vessels, and a Stone. All which I have already described in the First Book. Ch. 6. I shall here add, and further clear some things. And First, it is to be noted, That, in Proportion to the Bulk of the Fruit, there are more Vessels in a Plum, than in an Apple, Pear, or Quince. As also, That in Plums, all the Vessels are braced together into one Uniform Piece of Net-Work, every where terminating at an equal distance from the Circumference, sc. ⅛ᵗʰ of an Inch or thereabout. Tab. 68. And as for the Bore of the Aer-Vessels, although the Glass I used, when I examined this Fruit, would not reach it; yet is it to be presumed, that they bear a just Proportion to those in the Trunk of the same Tree; and that therefore they are here larger, than in an Apple or Pear. The Skin likewise of a Plum, is more fibrous, thick, and tough, than in those Fruits. The Ends of these Diversities, we shall presently speak of.
2. §. Of the Stone, amongst other particulars wherein the contrivance of Nature is very admirable, I have formerly shewed, B. 1. Ch. 6. That it is composed of Two or rather Three distinct Bodies. One of them, the Lining; which answers to the Coar in a Pear. And is originated from the Parenchyma, which the Seed-Branch brings along with it, through the Chanel in the Side, and at last into the Hollow, of the Stone; and is there spread all over it: as when a small Glass-Pipe, is blown and expanded into a Bubble. Tab. 68.if a Bladder, being stretch-out, and put through the Neck of a Bottle; were then blown up, so as to be every where contiguous to the Sides, and become, as it were, the Lining of the Bottle.
3. §. The Foundation or Ground of the Outer and more Bulky Part of the Stone, is the Iner Part of the Parenchyma; and answers to the Acetary in a Pear. Tab. 68. As the Fruit grows, the Tartareous Parts of the Sap, being continually precipitated upon this Parenchyma, it is hereby petrify’d. As will best be seen, by comparing the several Ages of the same Fruit together. And in some Stones; on the Surface whereof, some of the said Tartareous Parts appear in distinct Grains. Tab. 68. So that whereas in a Pear, the Calculary and the Acetary are distinct, here in a Plum, they are thrown one into the other. Or, as some Mineral Waters only make a Crust about a Stick or other Bodies immersed in them; but others, by sinking into these Bodies, do hereby petrify them: So in a Pear, the Tartareous Parts of the Sap, only make a Crust about the Acetary; but in a Plum, they sink into the Body thereof, or that Part of the Parenchyma, which stands in the place of it, whereby it is converted into a Stone. The Figures of Stones shall hereafter be spoken of, when I come in the next Part, to the Covers of the Seed.
4. §. AN APRECOCK is of the Plum-Kind. But some things are herein better observed. As first, the Position of the Bladders of the Parenchyma. For the Tartareous Parts of the Sap not being here dispersed, in little Grains, throughout the Fruit, as in a Pear; but all thrown off into the Stone: the Bladders therefore are so disposed, as not to have respect to several Centres, as in a Pear; Tab. 68. but only the Stone, to which they all do most exactly radiate; thereto conveying the feculent Sap, in so many little Streams. This is best seen, when the Fruit is full ripe.
5. §. In this Fruit, while it is young, the gradual transmutation of the Inner Part of the Parenchyma into a Stone, is also more apparent. And so are the Three Coats, which serve for the Generation of the Seed; being now all very distinct; and remarkable, not only for their Bulk; but also, the Analogy which they bear to the Three Membranes in many Viviparous Animals. Whereof I shall give a more particular Description, when I come, in the following Part, to the Covers of the Seed.
6. §. A PEACH hath a much bigger Stone, than either a Plum, or an Aprecock: and hath therefore, when full ripe, and especially in hot Countries, a more desecated or better fined Juyce. For the reason why the Stone is so great, is because the Vessels run so very numerously through the Body of it; and so cause a more copious precipitation of the Lees of the Sap thereinto.
7. §. A CHERRY is likewise near related to a Plum. But the Bracement or Reticulation of the Vessels, is here carried out further, Tab. 69. so as to be all round about contiguous to the Skin. And as the Aer-Vessels in the Branch of a Cherry-Tree, are larger than those of an Apple-Branch, but less than those of a Plum-Branch; so may they be presumed, to bear the same Proportion here in the Fruit.
8. §. A WALNUT, is a Nuciprune; or betwixt a Plum and a Nut, as a Bat is betwixt a Beast and a Bird. For the Rind, answers to the Pulp; and the Shell, as the Stone, is also lined. But the Seed-Vessels, which in a Plum run through a Chanel made on purpose in the Stone; do here enter, as in a Nut, at the Centre of the Shell. By which means, they are invested with a more fair Parenchyma; which Nature hath provided, as her Cloth, for the making of the Coats wide enough for so vast a Kernel.