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 and even in the ovule. In this order, oven the seed-leaves, fragments of stem, as well as parts still alive underground during the winter, may be easily known by their Raphides from planta of other and closely allied orders.

None of our exogenous trees or shrubs have, up to the present time, been found to produce Raphides, but they are present in many exotic trees and shrubs of this class. In the order Vitaceæ, of which the grape vine and American creeper are common representatives, we find both Raphides and Sphæraphides in the leaves, young shoots, ovaries, and ripe fruit. Our dictyogens abound in Raphides, as may be seen in the Black Bryony and Herb Paris. In the former they appear loose and destitute of a cell, both in the ripe berry-pulp, and the root stack. This root is like a little yam, and the yams so commonly used as food in the West Indies belong to this class, and contain Raphides.

The sarsaparilla of the shops affords Raphides, but not so the American or false sarsaparilla, which is one of the Araliaceæ, abounding in Sphæraphides.

In the other classes of our endogens, Raphides are more abundant than in our exogens. They are plentiful in the Hyacinth, the Star of Bethlehem, the Cuckoo-pint; also in the Lily of the Valley, the Asparagus, and in the Daffodil and other Amaryllids. We find them plentifully in most species of Duckweed, without the protection of a proper cell wall, the boundary of the space being formed merely by the outer walls of the contiguous tissue-cells. Raphides also occur in the English Orchidaceæ. They vary in length from 1-27th of an inch to 1-500th of an inch.

Sphærayfhides are more or less rounded forms, made up of a number of crystals, commonly opaque and whitish. They are generally rough on the surface, from the projections there of the crystalline angles. They vary very much in size in the same plant, and still more in different orders, and are universally diffused through Phanerogamia. Some plants of the Cactus tribe, when aged, have their tissues so loaded with them as to became quite brittle. The leaves or stem of the Hop, Nettle, and many Goose-foot weeds, are good plants for Sphæraphides; and so are the Begonias of our greenhouses. They are very large in the Prickly Pear.

Crystal prisms are also acicular forms, but seldom occur more than two, three, or four in contact, and then closely side by side, as if partially fused together. They are more frequently strewed singly throughout the plant tissue, and sometimes, as in the bulb-scales of Shallot, they form crosses. They are generally larger than the Raphides, and can be plainly seen to possess three or four faces or angles; they do not taper at the ends like the Raphides, but their tips are either pyramids, or like a carpenter's chisel, or wedge-shaped, or the ends may be truncate, an appearance often caused by fracture. These crystals, when they lie in contact, are not easily separable from each other, or from the tissue in which they are seated, and when the cell can be seen it is closely