APPENDIX, 
553 
» The Leaves of multitudes of plants contain the various kinds in 
great abundance; Pisonia, Hemerocallis, and Calla aethiopica 
furnishing the acicular, whilst Rheum palmatum and undulatum 
are common examples yielding the conglomerate. 
“ The Stipules are not without Raphides, for those of the Grape 
vine show them in situ, but very small in size. 
“ The Sepals many Orchidaceae abound with crystals, as those 
of Bolbophyllum fuscum and others, and especially the horny 
labellum of Catasetum. 
“ The Petals of many plants, like the sepals, contain more or less 
crystalline matter, which is particularly evident in the small corolla 
of the Grape vine. 
The Fruit does not so often contain them, yet the common 
Grape furnishes a sufficient evidence of their existence in that 
organ. 
“ In the Root their presence can be easily discovered, especially 
in all Rhubarbs, varying a little in number from the locality of 
the specimen ; most in Turkish, less in East-Indian, and least in 
British-grown specimens. 
“ Number in a Cell. — The number of Raphides in any cell is 
subject to much variation. It is seldom that a single crystal is 
met with ; but in the Squill, Calla aethiopica, and other examples, 
besides the multitude of acicular crystals, some cells which are 
not dilated occasionally exhibit only one minute rhombohedron, 
as has been observed by Unger in Papyrus antiquorum. Of 
the conglomerate kind, one cluster is the usual number in the re- 
spective cells, though in Zamia pungens two such can be at times 
observed within the same cell. The acicular Raphides are in the 
greatest numbers, and vary somewhat in quantity in different 
cells and in different plants ; some containing but very few, whilst 
others contain hundreds. 
a Proportion to the Weight of Tissue . — The mass of crystalline 
matter that is formed in the tissue of some plants is prodigious, 
whilst in others the quantity is very thinly diffused. In several 
species of Cactaceae the crystals equal if not exceed the weight 
of dried tissue ; this is especially the case in Cereus senilis. In 
Turkey rhubarb root, one hundred grains yielded between thirty- 
five and forty grains of Raphides ; and the fact of various rhubarbs 
giving different feelings of grittiness to the teeth when chewed, 
is said by Guibourt to be employed as the test of their goodness. 
In the bulb of Scilla maritima, not more than ten grains are con- 
tained in the same weight of dried tissue. . 
