THE SEEDLING AND YOUNG PLANT 65 
spindle-shaped fibres much like the fibres of the 
wood, 
As a rule, the outer and inner side of these bast 
groups are in contact with vertical rows of nearly cubical 
parenchyma cells, strongly thickened on the side next 
the bast, and each nearly filled with a crystalline clump 
or with an imperfectly formed crystal of oxalate of 
lime. Similar vertical rows of crystal cells may also 
occur within the groups of bast fibres, the walls of the 
cubical cells being more or less thickened and simply 
pitted. Occasionally a cell here and there retains thin 
walls. The vertical rows result from cross-divisions of 
prosenchymatous mother-cells, the conical ends being 
found in macerations. 
Within the groups of bast fibres are yet other rows, 
similarly formed, of parenchyma (fig. 17, bp), the cells of 
which are longer, however, attaining the length of the 
wood-parenchyma; like the latter also their walls are 
lignified and rather thick, and they contain starch in 
the winter. Thus we have parenchyma in the bast. 
Transitions between these two forms of parenchyma 
cells are also found. 
The cells of the rays between the bast fibres are 
thickened and pitted; they are rounded, and not in 
vertical series as in the rest of the rays, but are scattered 
in no particular order. Sometimes they are few, and 
one or all with very thick walls perforated by pit-canals 
(fig. 17, bs). 
The remaining younger part of the bast consists 
F 
