ON THE CUTICLE OF PLANTS. 321 
The cuticle in all cases appears to be a continuous membrane 
in which at the commissures of the subjacent epidermal cells 
there is no evidence that it is composed of single pieces which 
correspond with the outer walls of these cells. The outer sur- 
face of the cuticle is either perfectly smooth or distinguished 
with straight (Rumex Patientia) or irregularly branched (Hel- 
leborus fetidus) raised lines, which frequently run uninter- 
ruptedly over the commissures of the cells; or it is studded 
with smaller or larger granules, as is the case with many 
hairs, e. g. in those of Campanula Medium, many Boraginee, 
&c. These granules exhibit frequently on the hairs a spiral 
arrangement, and not unfrequently on the lower portions of 
the hair pass by extension into obliquely running streaks; 
whence it appears clearly that the raised lines and the 
isolated granules are formations of the same kind, and differ 
from one another only in form. In a transverse section of 
the leaf of Helleborus foetidus and Dianthus plumarius, it is 
clear that these raised stripes are indicative of so many folds 
in the whole membrane. j 
= The epidermal cells are often dotted; commonly, as in 
Vanilla planifolia, only on the lateral and inner walls ; more 
rarely, as in Cycas revoluta and Elymus arenarius (fig. 1), on 
the outer wall also. In those cells in which the outer wall 
is thicker than the lateral walls, the deposition of secondary 
Coats, on which the incrassation of the outer wall depends, 
Seems not to take place in all cases in the same way. In 
many plants, as Dianthus, the secondary coats of the lateral 
- walls evidently are continuous with those secondary coats 
Which in the outer wall of the cell lie immediately beneath 
the primary membrane, and there are found on the outer 
wall under the above noted coat still more interior coats, 
Which are not continued upon the lateral walls, or of which 
* In consequence of the generally toothed commissures of the epidermal 
cells in grasses, a peculiar crossing of the canals of the dots which Jie in 
the angle of these walls with those of the proximate cell takes place in the 
Point of juncture of the outer and lateral walls. 
