and in other jparts of the order Leguminosse. 263 



much larger. As to form, they are both simple and compound ; 

 they generally belong to one or other of the prismatic systems, and 

 among them may be seen rhombs, cubes, tetrahedrons, lozenge- 

 shapes, parallelepipeds, and hexagonal prisms. The crystals are 

 often hemiedral or unsymmetrical, and indeed as frequently so 

 irregular in outline as to present it curved or broken, quite unlike 

 that of a regular saline crystal, and resembling a starch granule, or 

 contracted at the sides like a dice-box, or, more rarely, bulging 

 there like a rolling-pin or skittle. Such forms, by the tests of 

 acids and iodine, are easily distinguishable from starch ; and none 

 of them are ever so elongated as the objects which, under the name 

 of crystal prisms, I bave long since distinguished from raphides. 

 In Leguminosae the crystals are commonly in strings of cells, with 

 one crystal, rarely two or more, in the centre of each cell ; and 

 thus is formed a system of crystalline fibres, running parallel, as 

 already mentioned, to the fibro-vascular bundles (Plate XLIV., Figs. 

 4, 5, and 6). But not always thus ; for in many instances the crystals 

 are regularly dotted throughout a membranous part, as may be 

 well seen, for example, between the nerves of the calyx of Trifolium 

 (Plate XLIV., Fig. 8), and so presenting a pretty form of a crystal- 

 line tissue. 



Confusion of Terms and Vagueness of Knowledge, — So common 

 are minute crystals of one form or other in flowering plants, as to 

 have arrested the attention of the earlier observers ; but the know- 

 ledge we at present possess of the distribution in the vegetable 

 kingdom of the crystals depicted in Plate XLIV., is still but little in 

 advance of what it was at the time of Schleiden's ' Scientific Botany.' 

 This frequent presence of such crystals in one or other part of 

 numerous widely different orders of plants, and the still t'urther 

 confusion arising from the misuse of terms, has made more difficult 

 the discovery of any rule concerning the occurrence of any special 

 form of crystals in particular parts of the frame of the species of 

 the manifold vegetable genera or orders. All microscopic crystals 

 in them, of what form soever, were confused together, under the 

 name of raphides, up to the advent of my researches ; and are still 

 too often so confounded, to the obstruction of botanical science, even 

 by some of the most eminent botanists. Thus, in the latest edition 

 of Henfrey's ' Course of Botany,' the subject is perfunctorily and 

 erroneously treated ; and in the recent and much-esteemed ' Treasury 

 of Botany ' there is no notice wh-itever of either crystal prisms or 

 sphaeraphides, and only the word raphides occurs, with this defini- 

 tion : " Crystals of various salts formed in the interior of plants by 

 the combination of vegetable acids with alkaline bases." Thus we 

 still have sad work in books of high pretensions ; and the more so 

 as there is to be found in older and popular dictionaries, making no 

 point of botany, shorter and more accurate definitions, as may be seen, 



