362 
DUNCAN S. JOHNSON 
Starch-filled perisperm cells of the ripe seed (figs. loi, io8, iii). 
The starch grains of the perisperm cells are, as in the seeds of P. 
pellucida and other species, grouped in the several distinct vacuoles of 
each cell, to the number of often 1,200 or 1,500 in a single vacuole. 
The nucleus of the ripe perisperm cell is usually squeezed up in a small 
central or lateral portion of the cytoplasm between the vacuoles. 
There is sometimes present also a large rounded body, staining slightly, 
which, like that found in Peperomia pellucida (Johnson 1900a, fig. 15), 
is probably to be regarded as a leucoplast. The cells of the outer 
layer of the nucellus, including those above the embryo sac, have much 
less starch than the central cells. In the ripe seed the starch has 
entirely disappeared from several layers of the cells next the embryo 
sac. The walls of the cells nearest the sac have completely collapsed 
(figs. 89, 108). This perisperm, with its starch, is absorbed through 
the endosperm at the time of germination, as in P. pellucida, which 
will be shown later (fig. iii). 
The integument is initiated soon after the carpel closes in above 
the ovule, chiefly by the activity of the epidermal cells of the base of 
the young ovule (figs. 56, 57). This ring-like outgrowth continues 
pushing upward as the nucellus elongates and closes together above to 
form the micropyle, before the time when the embryo sac has reached 
the sixteen nucleate stage (figs. 74, 78) . The integument is two-layered 
at first, and most of it remains so (figs. 68, 78, 100). At the base of the 
ovule and occasionally near the micropyle, it may become three-layered 
as the fruit approaches maturity (fig. 108). The cells of the outer layer 
of the integument never thicken appreciably on the sides of the fruit, 
but collapse and are finally crushed between the inner layer of the 
integument and the inner layer of the carpel (figs, loi, 108). At the 
base and the apex of the ovule one or both of the outer layers of the 
integument may be thickened like the inner one (figs. 100, 108). 
This inner layer consists of cells which are thin radially aud isodi- 
mensional in the other two directions (figs. 100, loi). The nuclei 
remain large and active until a late stage of development. The inner 
and outer walls attain a thickness of .5 )U or .7 )U, and have a dark 
brownish color in unstained material. Near the micropyle the inner 
walls of these cells are thrown into strong folds and protuberances, 
giving them a very irregular outline in section (figs. 89, 100, 108, cf. 
Johnson 1900a, fig. 15; 1910, fig. 68). The nuclei of these cells are 
large and active at first, but later these and the other cell contents 
