John Lindley, Edwards's Botanical Register, Appendix to the First Twenty-three Volumes…
“ Drummond says, that "the bulb is renewed every year in the centre of several layers of bark-like substance, one of which layers is added every year by the decay of the old bulb. If the young bulb is dissected at the time when the plant is in flower, the layer of fibrous substance, which afterwards becomes the covering, is easily perceptible; it terminates in a point, which the following season becomes a root, and another root is produced from the bottom of next year's flower-stalk. In planting these roots the fibrous substance should not be removed, or the plant will not thrive. ”
