As likewise for the security of its _Sap_: For by this means it is, that the several Fibres, and especially the main or middle Fibre of the Leaf, together with a considerable part of the _Cortical Body_, are so disposed of, as to jut out, not from its upper, but its back, or nether plain. Whence the whole Leaf, reclining backward, becomes a Canopy to them, defending them from those Injuries which from colder Blasts, or an hotter Sun, they might otherwise sustain. So that by a mutual benefit, as these give suck to all the Leaf, so that again protection to these. These Fibres are likewise the immediate visible Cause of the shape of the Leaf: For if the nethermost Fibre or Fibres in the Stalk be in proportion greater, the Leaf is long, as in _Endive_, _Cycory_, and others: If all of a more equal size, it spreads rounder, as in _Ivy_, _Doves-foot_, _Colts foot_, &c. And although a _Dock-Leaf_ be very long, whose Fibres notwithstanding, as they stand higher in the Stalk, are disposed into a Circle all of an equal size; yet herein a peculiar fibre, standing in the Center betwixt the rest, and running through the length of the Leaf, may be observed. In correspondence also to the size and shape of these Fibres, is the Leaf flat: In that either they are very small, or if larger, yet they never make an entire Circle or Ring; but either half of one, as in _Borage_, or at most three parts of one, as in _Mullen_, may be seen. For if either they were so big, as to contain; or so entire, as perfectly to include a _Pith_, the Energy of the _Sap_ in that _Pith_, would cause the said _Lignous Ring_ to shoot forth on every side, as it doth in the _Root_ or _Trunk_: But the said Fibres being not figur’d into an entire Ring, but so as to be open; on that hand therefore where open, they cannot shoot any thing directly from themselves, because there they have nothing to shoot; and the _Sap_ having also a free vent through the said opening, against that part therefore which is thereunto opposite, it can have no force; and so neither will they shoot forth on that hand; and so will they consequently that way only which the force of the _Sap_ directs, which is only on the right and left. The several Fibres in the Stalk, are all inosculated in the Leaf, with very many Sub-divisions; according as these Fibres are inosculated near, or at, or shoot directly to the edge of the Leaf, is it even or scallop’d. Where these Inosculations are not made, there we have no _Leaves_, but only a company of _Ramulets_, as in _Fennel_. The Formations and Fouldings of Leaves have one Date, or are the contemporary works of Nature; each Leaf obtaining its distinct shape, and proper posture together; both being perfect, not only in the outer, but Central and minutest Leaves, which sometimes are five hundred times smaller than the outer; both which in the Cautious opening of a _Germen_ may be seen.