Leaf Arrangement

Abstract

AFTER reading Dr. Airy's paper on Phyllotaxis (NATURE, vol. vii. p. 343), I cannot see that we are at all nearer than before, any satisfactory explanation as to the inherent cause of it. Let the question be put thus:—If we can conceive, as all will admit, the possibility of leaves being scattered anyhow along a branch, why are they not so, but in some strictly mathematical order? Any disturbance in that order is usually so slight and trivial (due apparently in part to the conical nature of the axis, and unequal growth or slight twists; and which thereby cause certain leaves to assume slightly wrong positions), that it does not destroy the fact that they absolutely are arranged, and can be represented, mathematically.