LEMNACE2. 19 
mineral substances, as silica and carbonate of lime, also sulphate of hme, are found in 
a crystalline form in the tissues of plants; but they do not constitute what are called 
raphides. 
In a paper on “ Raphides as Natural Characters in the British Flora,’ in the 
volume of the “Quarterly Journal of Microscopical Science’ for 1866, Professor 
Gulliver gives the following summary of the occurrence of raphides in British 
plants :— 
“Only three orders of British Dicotyledons can be as yet characterised as raphis- 
bearers, and these are Balsaminesw, Onagracer, and Rubiacee.” ‘ In Monocotyledons 
raphides are much more plentiful than in Dicotyledons, so no wonder that a partial 
examination should have led to the belief that ‘they are abundant in Monocotyledons 
generally.’ This and other such vague and incorrect statements are current in our 
best and latest treatises of Phytotomy ; whereas the truth is, that, however raphides 
may abound in many Monocotyledons, they are either very scarce or absolutely wanting 
in several extensive orders of this class. As before mentioned, our indigenous plants 
are only now under consideration, and we shall soon see that about a fifth part of the 
‘Manual of British Botany’ is occupied by Monocotyledons and Cryptogamess 
Ductulose, which I have searched in vain for raphides. 
“ Dicotyogene.—In all our plants of this group raphides are plentiful, and they occur 
in every one of the exotic members of it that I have examined; only in Rowburghia 
raphides are mostly replaced by crystal prisms. I have found that the beautiful 
shrub Lapageria is also a raphis-bearing plant. In the lineal series of the natural 
arrangement, the Dicotygen stand isolated by this character between Coniferse and 
Hydrocharidacex, two orders in which it is wanting. 
_ “ Hydrocharidacee.—This order is remarkable as being devoid of the raphidian 
character, though standing between two groups, Dictyogene and Orchidacee, in full 
possession thereof. 
“ Orchidacee.—Raphides were found in every plant, British and foreign, that I have 
examined of this order. They are by no means confined to the sepals, as might be 
supposed from current descriptions, but are common in the placenta and ovary, in 
the stem and the leaves, and parts which are modifications of leaves, and in the roots. 
The raphides are commonly much shorter than their soft pale cells, and may be well 
seen without disturbing them through the semitransparent edge of the leaf of Neottia 
spiralis. 
“ Tridacee.—True raphides are scanty and often not to be detected in this order, 
but it abounds in crystal prisms. These last occur in all our plants except Sisy- 
rinchiwm anceps, in which, as well as in the exotic S. Bermudianum, and S. striatum, 
Thave failed to find any such crystals. They are very remarkable in the common 
_ garden species of Iris. 
“ Amaryllidacee.—In all our Amaryllids raphides occur. They may be well seen in 
_ the leaves, scape, ovary, bulb-scales, and bulb, and smaller and less plentiful in the 
bulb and perianth. 
“ Asparagacee.—All our plants of this order are raphis-bearers. This character is 
_ common in the root, leaves, perianth, and ovary of asparagus, &c., and more remark- 
able in the perianth than in the leaves of Ruscus. 
_ “ Tiliacee,—Of the four tribes of this order as they stand in the ‘Manual of British 
Botany ’"— 
“1. Tulipee. Destitute of raphides. 
“2. Asphodeleew with Gagea and Allium. Also devoid of raphides, though they 
abound in Ornithogalwn and Scilla. 
D2 
