Mode of increase by Buds the same in recent and fossil Cycadeæ.
The Cycas revoluta figured in Pl. 58[1] possesses a peculiar
interest in relation to both our fossil species, in consequence
of its protruding a series of buds from the axillæ of many of
the scales around its trunk. These buds explain analogous
appearances at the axillae of many fossil scales on Cycadites
trunk towards the leaf. On the lower integument, (b') is a dense coating of minute curling filaments of down or cotton, (a) which being repeated on each scale, renders the congeries of scales surrounding the trunk, impervious to air and moisture.
A similar disposition is seen in the longitudinal section of the fossil Petiole of Cycadites microphyllus represented at Pl. 62, Fig. 2, and magnified four times. At a we have cellular tissue interspersed with gum vessels, h. Beneath c, are longitudinal bundles of vessels; at b, is the integument; at a, a most beautiful petrifaction of the curling filaments of down or cotton, proceeding from the surface of this integument.
In the vascular bundles within the fossil Petioles, (c) Mr. Brown has recognised the presence of spiral, or scalariform vessels (Vasa scalariformia) such as are found in the Petioles of recent Cycadeæ; he has also detected similar vessels, in the laminated circle within the trunk of the fossil Buds next to be described. The existence of vessels with discs peculiar to recent Cycadeæ and Coniferæ, such as have been described in speaking of fossil Coniferæ, has not yet been ascertained.
- ↑ This plant had been living many years, in Lord Grenville's conservatory at Dropmore. In the autumn of 11827, the external part of the scales was cut away to get rid of insects: in the following spring the buds began to protrude. Similar Buds appeared also in the same conservatory on a plant of the Zamia spiralis from New Holland. In vol. vi. p. 501, Horticult. Trans. leaves are stated to have protruded from the scales of a decayed trunk of Zamia horrida in a conservatory at Petersburgh.
I learn from Professor Henslow, that the trunk of a Cycas revoluta, which in 1830 produced a Cone loaded with ripe drupæ, in Earl Fitz-william's hot-house at Wentworth, threw out a number of buds, from the axilla: of the leaf-scales soon after the Cone was cut off from its summit. In Linn. Trans. vol. vi. tab. 29, is a figure of a similar cone which bore fruit at Farnham Castle, 1799.
It is stated in Miller's Gardener's Dictionary, that the Cycas-revoluta was introduced into England about 1758, by Captain Hutchinson; his ship was attacked, and the head of the plant shot off, but the stem being preserved threw out several new heads, which were taken oil] and produced as many plants.
