Prof. G. Gulliver on Raphides and other Crystals in Plants. 331 29. M. peronaeo-calcaneus. Origin : from lower part of shaft of the fibula. Insertion : into the upper surface of the calcaneum. 001 oz. XXXVII. — Observations on Raphides and other Crystals in Plants. By George Gulliver, F.R.S. [Continued from p. 117.] Vitacea and Araliacea. — In the last communication ('Annals' for Aug. 1865) it was stated that raphides abound in all the plants, therein specified, which I had examined of the order Vitacese, while every species of the allied or related orders, of which comparative examinations were made, proved to be devoid of this raphidian character. I have had an opportunity, through the courtesy of a botanical friend, of dissecting a dried fragment of the receptacle-stalk of that most curious plant, Pterisanthes {Vitis Pterisanthes, Mic, /S. boimeensis), a bit of the dried leaf-blade and fruit-shell of Bersama abassynica, Fresen., and a part of the dried leaf and flower of Natalia lucens, Hochst. {Rhaganus lucens, E. Meyer). To the same genus, I have been told, Ber-sama abassynica is referred by Hooker and Bentham. Pterisanthes, like Vitis, Cissus, and Leea, abounds in true raphides and sphaeraphides. The raphides of Pterisanthes are about T-Q-oth of an inch long and mloo thick; the average diameter of the sphseraphides is ^-jJo-oth of an inch. The Ber-sama and Natalia are destitute of true raphides, but contain numerous crystal-prisms, about -o^Trth of an inch long and .^.^'sti th thick. These may be well seen in the leaf and inner membrane of the fruit-shell of Bersama, and in the leaf, calyx, petals, and pedicel of Natalia. The prisms have four equal faces, and their ends slope off either from angle to angle or from face to face. Thus species of all the genera adopted by Lindley under the order Vitacese — Cissus, Vitis, Pterisanthes, Leea, and Rhaganus — have now been examined, though too often in imperfect or unsatisfactory fragments ; and in every one of these plants true raphides were found, except the Bersama and Natalia {Rhaganus), in which raphides are replaced by crystal-prisms. It may be recollected that a like phenomenon occurs in the last order (Roxburghiacese) of the raphidian class Dictyogense, as described in the 'Annals' for June 1865. Of Araliaceffi and Vitacca, the comparative structure in the leaves and some other parts has already been described ('Annals ' for August 1865). 1 have lately examined fresh leaves and twigs of Aralia spinusa, and a bit of a dried leaf-blade of A. racemosa.
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