1 6 Saunders . — On the Structure and 
owing to an increased formation of granular substance in 
the cells — probably a deposition of granules of meta- 
plasm in the cell-protoplasm. The starch-grains are 
larger as well as more numerous, and their outline is 
more distinct ; they are frequently arranged in a more or 
less complete ring round the nucleus, though a few are 
sometimes scattered in the more remote parts of the cell. 
( b ) The depth of the sub-epidermal cells is generally greater 
than their width, i.e. they are elongated in a direction 
perpendicular to the lumen. 
(a) The nucleus is central or parietal, in the latter case 
it is frequently more or less flattened. 
(f3) The changes in the cell-contents are similar to 
those which occur in the epidermis ; at first during the 
rapid growth of the cells distinct vacuoles are formed, 
later there is a slight increase in the granular cell-con- 
tents. The vacuolation however is generally carried to 
a greater extent, and the deposition of the metaplasmic 
granules is less marked than in the epidermal cells. 
Starch is very abundant, large grains occurring in all 
parts of the cell. Both here and in older flowers most of 
the large grains of starch which appear to be simple are 
in reality compound ; by treatment with potash and 
iodine they can be shown to consist of several small 
grains held together by the ground substance of the 
plastid, which only becomes obvious after it is swollen by 
some reagent. 
C. Flower-tube open, anthers still closed (Fig. 6). 
(a) The epidermal cells show much the same characters as 
in the older buds, but in a more pronounced form. 
(a) The mucilaginous swelling of the external wall, 
which has now become distinctly convex, is greater, and 
the corroded appearance of the internal surface more 
marked ; in most cells the upper part of the lateral walls 
is also involved in the former change ; the narrow ex- 
ternal layer is obvious here and in all later stages. 
