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Kidd and West . — The Controlling 
iv. A layer of narrow radially elongated cells with characteristic 
highly refractive thickenings of the inner and radial walls (Text- 
fig. 5, A and B). These cells have coarsely granular contents 
and distinct nuclei. 
The layers numbered v-vii in Text-fig. 5, A and B, constitute the so- 
called inner testa or seed-coat* 
v. A layer, several cells in thickness, of delicate thin-walled tissue which 
appears totally collapsed and crushed in the ripe seed. The walls 
of these cells give the pectin reaction with ruthenium red. 
vi. A layer of moderately large cells with dense granular contents and 
large nuclei. In the ripe seed these cells form a very 
B, 
Text-fig. 5. 
characteristic compact layer (Text-fig. 5, A). The walls of these 
cells give the pectin reaction with ruthenium red and are 
insoluble in cuprammonia. The cell contents consist of proteid 
granules and oil. 
viio A layer, many cells in thickness, of delicate tissue, the cells of 
which appear totally collapsed and crushed in the ripe seed. 
The walls of these cells give the reactions characteristic of 
cellulose with Congo red and with chlor-zinc-iodide. They do 
not stain with ruthenium red. Since, however, they are 
insoluble in cuprammonia, they probably consist of hemi- 
cellulose. 
