24 
HISTOLOGY OF VEGETABLES. 
square, the oblong, and the lobed ; in the section of 
the rind of a Gourd , represented by Fig. 13, you will 
notice, that cells more or less cubical may become 
prismatic, or even be so much compressed towards one 
edge, as to assume the appearance of fibres. There are, 
however, some of the varieties which demand a more 
FIG. 13 . 
FIG. 14 . 
Vertical section of the rind of a 
Gourd. 
Stellate cells from the young petiole 
of Sparganium ramosum. 
particular description ; one of the most remarkable 
of these is the stellate cell, which is found in the 
pith of some rushes, the petiole of the sweet Burr- 
reed (Sparganium ramosum ), and in the stems of 
many aquatic plants. In the young petiole of the 
Sparganium there are strata of hexagonal cells which 
form septa ; these, as shown in Fig. 14, have around 
their margins certain notches, which, with those in 
adjacent cells, from triangular apertures, known to 
botanists as lacunae ; in process of growth these notches 
become deeper and deeper, the lacunae, aa, enlarging at 
the expense of the area of the cell-wall, which gradually 
