552 
APPENDIX. 
cell, which cell is applied closely to the surface, the crystal com- 
pletely filling it : when muriatic acid is added the crystal is 
dissolved, and the cell is left visible. 
“ The most ready method of determining that the acicular crystals 
are contained within the cells is, to take a piece of the bulb of 
Scilla maritima and macerate it until it becomes decomposed, or 
to take some of the rotten portions which are frequently on its 
exterior ; and, by examining either of these with the microscope, it 
will be seen that there are numbers of isolated cells which contain 
crystals, which cells are five or six times larger than those of the 
tissue which have none within them ; and, what appears remark- 
able, the crystals seldom occupy more than a small portion of the 
cell though it be so dilated, and in the Squill are usually collected 
at one end, probably by gravitation ; but in the biforines they 
generally completely fill a small portion of the cell, about its 
middle, the ends containing none whatever. 
“ To prove the same fact as regards the conglomerate kind, let a 
piece of the root of Rhubarb, or a part of the frond of Zamia 
pungens, be boiled till the cohesion of the tissue be destroyed, 
when some of the separated cells will exhibit one cluster generally 
in each ; but the containing cell is not larger than others of the 
same plant, and at times very little larger than the mass within it. 
“ There are some exceptions to Raphides being found constantly 
in cells, notwithstanding Unger’s assertion that they are exclusively 
found in their interior, and that the vascular bundles have none 
within them : for they can be observed in the interior of the vessels 
in the stem of the Grape vine ; and loose in the anthers, mixed with 
the pollen, in Hemerocallis purpurea, Anigozanthus flavidus, and 
many other plants ; and they can be observed in the air cavities of 
and many aquatics. 
“ The interior of the Stem is the most common situation in the 
herbaceous plants for Raphides, and it used to be considered the 
only locality ; but the epidermis of the stem of many plants dis- 
plays thousands, as that of the Tradescantias, Opuntia crassa, 
others. 
“ The Bark of many trees also contains them ; they are readily 
observed in the layers of the Lime tree bark, of two kinds : also in 
the barks of Araucaria imbricata, Cascarilla, Cinchona, and various 
other plants. 
“ Even the Pith is not destitute of crystals ; for the Grape vine 
exhibits them in that situation, as does the Lime tree in the me- 
dullary rays, which are processes connected with it. 
