120 Prof. G. Gulliver on Raphides. 
bundles of raphides. Thus raphides are plentiful in the two 
herbaceous species, and are replaced or represented by sphe- 
raphides in the two shrubby plants. I have elsewhere (Quart. 
Journ. Microsc. Sc. for Jan. 1864) noticed the scarcity of ra- 
phides and abundance of other crystals in trees and shrubs. 
Aracee.—Prof. Balfour has for many years used the ovaries 
of Arum for furnishing raphides to the pupils of his histo- 
logical class, and Dr. Maclagan found these raphides to con- 
sist of oxalate of lime. The question of the composition of 
raphides is very important, and requires further research. They 
have often been described as a form of phosphate of that earth. 
Their abundance in the root of Smilaceze led me to look for them 
in the officinal extract of Sarsaparilla, in which no raphides could 
be found, though it contained numerous minute square crystals, 
some of which were distinctly seen to be such quadratic octa- 
hedrons as are commonly formed of oxalate of lime. The dif- 
ference between the raphis-cell and its surrounding cells is well 
depicted in fig. 38 of Prof. Balfour’s ‘Manual of Botany.’ Prof. 
George Lawson, of Canada, informed me that while he acted as 
histological demonstrator in Prof. Balfour’s class at Edinburgh, 
several years before 1859, he was frequently in the habit of 
employing Lemna trisulca for the purpose of showing raphidian 
cells*, 
Constancy of the Raphis-bearing character.—Raphides are 
produced, as we have before shown, in all stages of the growth 
of typical raphis-bearing plants, from the ovule to the seed- 
leaves, thence through the ascending and descending axes, and 
the appendages of the former and their modifications to the fruit. 
So little effect has either the soil or the situation in which the spe- 
cies flourishes on this important function of raphis-bearing, that 
it will continue as regularly during the entire vigorous existence 
of the plant as any common phenomenon of whatsoever kind in 
the cell-life of that plant. But though these conclusions are 
deduced from observations extending over the spring, summer, 
and autumn of several years, and sometimes on plants from 
various and dissimilar localities, the state of the raphides in the 
winter season was seldom inquired into. Hence I have repeated 
the examinations of such plants as could be easily procured be- 
* I have recently learned that Prof. Balfour long since observed the 
abundance of raphides in various Araceze, as Colocasia odora, Richardia 
@thiopica, and Caladium viviparum. Prof. Douglas Maclagan discovered 
the raphides in the oyary of Richardia, subjected them to chemical ana- 
lysis, and found them to consist of oxalate of lime. He looked at those of 
Arum, and concluded that they also are oxalate of lime (Trans. Bot. Soe. 
1861; Edinb. New Phil. Journ. new ser. xvi. 300). The raphides of Lemna 
trisulca, which Dr. Lawson was the first to use in the class demonstrations, 
were noticed in Prof. Balfour’s ‘ Class-Book of Botany,’ ed. 1855, p. 41. 
