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Show Book IV. The Anatomy of Leaves. 5. §. TO make this appear,I thall give feveral Inftances: of fome, where both the Edges are of one Meafure 5 and of others, where they are different. And ofboth kinds, where they are meafured byfewer? andwhere by moreCircles. CHAPSITE Of the Figure of the Leaf; and the Apparent Pofition of the Fibres. 6. §. The Leaf of Lagopus major fol. pennat. is meafured by One Gircle, the fame on both Edges, whofe Diametre is Thrice the Length ofthe Leaf. 7. §. That of syderitis Salvie fol. by Two Circles: the Diameter of the Lower, being Twice the Length of the Leaf; of the upper, 7p the Length and half. In both thefe the Circles are drawn Outward 5 ao: ate i qa Pit i HAT which in the Lesf offers it felf next to be obferved, is its Figure. This is infinitely va- ~ &Y ried with the feveral Kinds of Plants: and there That of Orange-Tree, is alfo meafured by Two Circles: but That next the Cone of are fome, which have Leaves (befides the two R firft Diffimilar ones.) of Two Kinds or Twodi- the Leaf, is drawn Inward 5 that is, with the Center no where upon the ftin&t Figures Leaf, but withoutit. The Déameter hereofis juft the Length of the Tab. 44. Leaf. The midle part of the Edge is meafured by the fame Circle, only drawn Outward. The lowerCircle next the Stalk, is drawn Inward, as the upper; and its Diameter Three times the Length of the others, as the Bitter-Sweet, the com- For the Under Leaves of Bitter-Sweet, are Entire; the Upper, with two Lobes: the Under Leaves of the Little Bell, \ike thofe of Paxcy; the Upper, like thofe of Carwation, or of Sweet-William. And in fome Plants, Nature affeteth a Kind of Irregularity 5 the Leaves whereof are of no one certain Figures as in Dragon, Peony, Bifhops-Weed, &c. 2.§. BUT the Leaves of moft Plants, have a Regular Figure; and this Regularity, both in Length and Circuit, always defineable. In Length ; by the Proportion between the feveral Leaves upon one Stalk , or between the feveral Lobes upon one Leaf: So the Leaves of Clematis Sylv. major, which ftand by Ternaries, fhorten by equal Proportions, that isto fay, if, the chief Fiber ofeach, be divided into equal Parts; their feveral Lengths are not as Ten,Eight,and Four ; but as Ten, Eight, and Six. So the Lobes and Fibers of Clematis Virgini- ana Hedere folio, of Artennifa, &c. fhorten in like manner by equal Proportions. The fameis obfervable in meafuring, upon a Goo/eberryLeaf, from the Poyntofthefirft Lobe, to the firft Angle 5 from thence, to thefecond Poynt; from thence, to the fecond Angle; and from thence to the third Poynt. 3- §. But in many, the Proportion is different, So in the Leaves of the Leffer Maple; the fhortning of the fmaller Lobes, with refpect to the middelmoft; is not Equal, but Double to that of the middlemoft, withrefpeét to the Greater. Forif their chief Fibres be divided into Equal Parts, they are as Eleven, Nine, and Five. Onthe contrary, in the Leaves of Althea fruticofa Pentaphylloidea, the middlemoft Lobes fhorten by a greater Proportion than the Leafts, all three being as Ten, Fourteen, and Twenty. 4. § 8. §. one of them repeated with Oppofite Centers. YS) d mon Little Bell, Valerian, Lady-Smocks , and S that is, with their Centers fome where uponthe middlemoft or chief Fiber of the Leaf: WITH refpet to the Circumference, the Figure of moft Leaves is very Complex. Yet Two things are evident. Firft, that all Regular Leaves,are defined or meafured out byCircles 5 that is, by the Arches or Segments of feveral Circles, having either the fame, or divers Centers and Diameters. Secondly, That the Length of the Leaf, or of the chief Fiber thereof, is the Standard Meafure for the Diameters of thefe Circles: thefe being either its full Length, or certain equal parts fubftratted, or multiplied; as half itsLengt h, or its Length and half &c. 5. f- Leaj. if §. cles. The Leaf of the Yenetian Vetch, is meafured by Three Cir- That next the Cove, drawn Inward; the Diameter whereof, is Twice the Length of the Leaf 5 the next is drawn Outward; whereof the Diameter, is juftthe Length. The third or lowermoft, is drawn alfo Outward ; and its Diameter, half the Length. Tab. 44. So that they all leffen by an Equal Proportion. to. §. The Leaf of Great Laferwort , is alfo meafured by Three Circles 5 all drawn Outward, and one of them Repeated. The Diameter of that next the Cone, is Half the Length of the Leaf; of the Tzb. 49. next, Thrice the Length; of the Third, juft the Length; the lowermolt, is the fame with the Firft. 18. §. That of Broad Leav'd Laferwort,is alfo meafured with Three Circles; and one of them repeated with Oppofite Centers. The Diameter ofthe Firft, is Half the Length of the Leaf; of the Second, Twice 4p. 44 the Lengths of the Third, juftthe Length: all of them drawn Outward. That next the Stalk, is the fame with the Firft; only drawn Inward. 12. §, The Figure ofthe Leafof the Cornelian Cherry,is exadtly that ofthe foregoing, Inverted: the fame meafure there beginning at the Tab. 44, Bafe, and ending at the Cone; which here beginsat the Cove, and ends at the Bafe: as by comparing their Draughts together may be obferv'd. 13. §. IN ALL,the foregoing Examples, both the Edges of the Leaves have the fame Aeafure. But they have oftentimes, different ones 5 as in thefe that follow. 14. §. The Leaf of Althea fruticofa,is meafured by Three Céreles. The left Edge (asthe Leaf lies with the backfide upward ) by One Circle, but Twice repeated. For the Diameter of the Firft, is the Length of Tab, 49. the Leaf 3 the Second is the fame, but drawn upon another Center5 the Third alfo the fame, but drawn Inward. The right Edg, is meafur'd by TwoCircles: the Diameter of the Firft, being the Length of the Leaf’; of the Second, Half the Length. 19. §. |