. A general system of botany, descriptive and analytical. In two parts. Part I. Outlines of organography, anatomy, and physiology. Part II. Descriptions and illustrations of the orders. By Emm. Le Maout [and] J. Decaisne. With 5500 figures by L. Steinheil and A. Riocreux. Translated from the original by Mrs. Hooker. The orders arranged after the method followed in the universities and schools of Great Britain, its colonies, America, and India; with additions, an appendix on the natural method, and a synopsis of the orders, by Hooker. Botany. 84 OEGANOGRAPHT AND GLOSSOLOGY. indicates the g
. A general system of botany, descriptive and analytical. In two parts. Part I. Outlines of organography, anatomy, and physiology. Part II. Descriptions and illustrations of the orders. By Emm. Le Maout [and] J. Decaisne. With 5500 figures by L. Steinheil and A. Riocreux. Translated from the original by Mrs. Hooker. The orders arranged after the method followed in the universities and schools of Great Britain, its colonies, America, and India; with additions, an appendix on the natural method, and a synopsis of the orders, by Hooker. Botany. 84 OEGANOGRAPHT AND GLOSSOLOGY. indicates the generating spiral. But the direction of this generating spiral from left to right, or right to left, depends on the angle of divergence; if the fraction be f, 01" T 3J o^ ifj and so on, the primitive or generating spiral wUl follow the most nume- rous secondary spirals; but if the fraction be -|, or /-j-, or fj-, &c., the generating spiral will follow the least numerous secondary spirals. Take, for example, the fraction |- (fig. 459 a), and let us examine the relation be- tween the genera- ting and secondary spirals. Whatever may be the direc- tion of the genera- ting spiral, the least numerous secondary spirals must follow the same, and vice versa. Suppose the spiral to be aright- to-left one, as in 459 a, it follows that, placing No. 1 where the radius touches the- outer end of the spiral, and successively numbering the leaves from ^ to f, the nearest radius to the left will be occupied by a leaf before the nearest radius to the right. The first leaf on the left radius will evidently be No. 4; for it will occur after traversing three ^ (-|); that is, after one entire revolution, plus i, and consequently on the left-hand radius nearest the one from which we started. The leaf which will be found on the right radius wiU evidently be No. 6, for it will occur after five times f (y), that is, after one re- volution minus ^, and consequently on the nearest right-hand radius.
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1873
