An Appendix.
Of Thorns, Hairs and Globulets.
THorns are of two kinds, Lignous and Cortical. Of the first are such as those of the Hawthorn, and are constituted of all the same substantial Parts whereof the Germen or Bud it self, and in a like proportion: which also in their Infancy are set with the resemblances of divers minute Leaves. Of affinity with these are the Spinets or Thorny Prickles upon the Edges and Tops of divers Leaves, as of Barbery, Holly, Thistle, Furze, and others; all which I think are the filamentous extremities of the Lignous Body sheathed in the Skin. But this principal difference betwixt a Bud and these Lignous Thorns, is observable; That the Bud hath its Original from the Inner part of the Lignous Body, next the Pith: But these Thorns, from the outer, and less fecund Part; and so produceth no Leaves, but is, as it were, the Mola of a Bud.
2. §. Cortical Thorns are such as those of the Rasberry Bush, being not, unless in a most extraordinary small and invisible proportion propagated from the Lignous Body, but as, it seems, wholly from the Cortical and Skin, or from the exteriour part of the Barque.
3. §. The Growth of this Thorn may farther argue what in the C. 2. §. 25. Second Chapter we supposed; sc. That as the proper Tendency of the Lignous Body, is to Ascend; so of the Cortical to Descend. For as the Lignous Thorn, like other Parts of the Trunk, in its Growth ascends; This, being almost wholly Cortical, pointeth downward. Hist. of the Prop. of Veget. The use of Thorns the Ingenious Mr. Sharrock hath observed.
4. §. Upon the Leaves of divers Plants two Productions shew themselves, sc. Hairs and Gloubulets. Of Hairs, only one kind is taken notice of; although they are various. Ordinarily they are of a Simple Figure; which when fine and thick set, as on most Hairy Buds; or fine and long, as on those of the Vine, we call them Down.
5. §. But sometimes they are Branched out, from the bottom to the top, reciprocally on every side, in some resemblance to a Stags Horn; as in Mullen. And sometimes they are Astral, as upon Lavender, and some other Leaves, and especially those of Wild Olive; wherein every Hair rising in one round entire Basis a little way above the surface of the Leaf, is then disparted, Star-like, into several, four, five or six Points, all standing at right Angles with the said perpendicular Basts.
6. §. The Uses of Hairs are for Distinction and Protection. That of Distinction is but secondary, the Leaves being grown to a considerable size. That of Protection is the prime, for which they were originally form’d together with the Leaves themselves, and whose service they enjoy in their Infant-estate: For the Hairs being then in form of a Down, always very thick set, thus, give that Protection to the Leaves, which their exceeding tenderness then requires; so that they seem to be veiled with a Coat of Frize, or to be kept warm, like young and dainty Chickens, in Wool.
7. §. Globulets are seen upon Orach, both Garden and Wild; and yet more plainly on Mercury or Bonus Henricus. In these, growing almost upon the whole Plant, and being very large, they are by all taken notice of.
8. §. But strict Observation discovers, that these Globulets are the natural and constant Off-spring of very many other Plants. Both these Globulets, and likewise the diversity of Hairs, I find that Mr. Hook hath also observed. Micrography.I take notice, that they are of two kinds; Transparent, as upon the Leaves of Hysop, Mint, Baume, and many more White, as upon those of Germander, Sage, and others. All which, though the naked Eye will discover, yet by the help of Glasses we may observe them most distinctly. The use of these we suppose the same, in part, with those of the Flower, whereof we shall speak.