The natural history of plants, their forms, growth, reproduction, and distribution; . Fig. 99.—Plan for Spiral Phyllotaxis. 1 One-lialf Phyllotaxis. 2 One-third Phyllotaxis. » Two-fifths Phyllotaxis. * Three-eighths Phyllotaxis. The conical steii)horizontally projected; the points of insertion of the leaves on the circumference of the stem marked by a dot. which may be connected by a spiral line, a genetic spiral, with five revolu-tions. The number of the straight lines here amounts to thirteen, and the distancebetween two leaves following one another in age is -^ of the circumference, i.
The natural history of plants, their forms, growth, reproduction, and distribution; . Fig. 99.—Plan for Spiral Phyllotaxis. 1 One-lialf Phyllotaxis. 2 One-third Phyllotaxis. » Two-fifths Phyllotaxis. * Three-eighths Phyllotaxis. The conical steii)horizontally projected; the points of insertion of the leaves on the circumference of the stem marked by a dot. which may be connected by a spiral line, a genetic spiral, with five revolu-tions. The number of the straight lines here amounts to thirteen, and the distancebetween two leaves following one another in age is -^ of the circumference, ° (see fig. 100). Not so common, or rather not demonstrable with the same precision, areinstances in which one story shows twenty-one leaves which are connected by agenetic spiral with eight revolutions; and where a story includes thirty-fourleaves which are connected by a genetic spiral with thirteen revolutions. In theone case any two leaves next one another in age in a story are separated from one DISTRIBUTION OF THE GREEN LEAVES ON THE STEM. 401 another ^ of the circu
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1902
