On some points in the Histology of 
Monocotyledons. 
BY 
JOHN PARKIN, M.A., 
Trinity College , Cambridge. 
With Plate XIII. 
I. Observations on the Raphides (Figs. 1-12). 
HEN recently examining microscopically a number 
V V of Monocotyledonous leaves and reserve-organs for 
the purpose of investigating the occurrence and distribution 
of carbohydrates in them, I also paid some attention to the 
raphides so often present, and accumulated certain facts con- 
cerning them, some of which are apparently new. It was 
my intention to make a more complete investigation of this 
class of calcium-oxalate crystals ; but at present, not having 
sufficient time at my disposal, it seems worth while to notify 
the few features that have come under observation. 
The word ‘ raphides,’ introduced first by De Candolle, is 
used to denote bundles of needle-shaped crystals which are 
arranged generally, but not necessarily, in a parallel manner. 
Each bundle arises in and occupies a single cell. Such cells 
I term raphide-cells. Although raphides occur in some 
Dicotyledons, they are pre-eminently characteristic of Mono- 
[Annals of Botany, Vol. XII. No. XL VI. June, 1898.] 
