48 
hitherto received much attention, either from Botanists or Micros- 
copists generally, but probably every one present was aware that a 
very large number of plan\s contained, within the cells of which 
they were composed, crystals of various salts of lime. For some 
time past all plant crystals of whatever shape had been confounded 
under the common name of ‘“‘ Raphides ;’”’ that name, however, was 
only properly applied to that particular form of crystal to which it 
was Originally given, viz., the needle-shaped or acicular. Professor 
Gulliver—to whose researches we owed almost everything that is 
known of these crystals—had classified them according to their 
form in the following order :—1st, Raphides ; 2nd, Crystal Prisms ; 
and 8rd, Spheraphides. The Raphides were generally found in 
small bundles within the cell; they presented less variety of form 
than the other crystals, differing only in size and comparative length 
and-breadth. They were to be easily obtained from the black -bryony, 
by simply squeezing out a drop of juice from a ripe berry on to a 
slide, when the raphides would be seen, some lying loosely about, 
while others remained in compact bundles. These crystals were to 
be found in a number of our native plants, amongst which were 
mentioned arum maculatum, lemna triscula, orchids, typha latifolia ; 
and amongst foreign plants, in the grape-vine, Virginian creeper, 
aloes, American poke-weed, &c. ‘The crystal prisms were the most 
varied in form of all; they were divided into the long and short 
prismatic crystals. They were found in the testa, or seed-coat of 
the elm; in the testa and pericarp of our wild geraniums ; in the 
leaves, calyx, and stipules of many representatives of the pea tribe ; 
as in our wild vetches, clovers, &c. The spheraphides were distinet 
from these two classes, and as to variety of form were intermediate 
between them. They were to be found in many of the pink tribe 
of plants, in the common dog-mercury, and in many representatives 
of the dock and nettle tribes. The value of these crystals in 
systematic botany, and the size and compositions of the crystals, 
were also explained by Mr. Beeby, who then proceeded as follows :— 
Respecting the office which these crystals fill in the economy 
of the plant, it has sometimes been maintained that they are no use 
whatever, but that they are merely of accidental occurrence—the re- 
sults of an abnormal condition of the plant. This, however, is not the 
case, though when once deposited they are probably of no further use 
to the plant, unless, as seems possible in some very succulent species 
in which they oceur in great quantities, they may act as a kind of 
skeleton to help in supporting the plant. As to the mode in which 
some of the crystals are deposited, I will read a sbort quotation from 
the text book of botany by Dr. Julius Sachs. He says, ‘ A large 
part of the calcium taken up by plants is precipitated by oxalic acid, 
and remains inactive. The importance of calcium must there- 
fore be sought partly in its serving as a vehicle for sulphuric 
