SEEDS AND FRUITS. 135 
for example, from the endosperm of castor-oil, shows them in the 
form of oval bodies crowding the small parenchymatous cells. 
Fach grain contains a crystalloid and also a rounded mass of 
mineral matter known as a globoid. A microscopic section 
through the cotyledon of a ripe pea shows that here numerous 
minute aleurone grains are associated with far larger oval starch 
grains. In wheat the external layer of endosperm cells contains 
aleurone only, the internal part starch only. ‘The preparation of 
flour for white bread involves the removal of this external highly 
nutritious layer. Hence the value of whole flour bread where it 
still remains (cf. p. 26). 
Starch is by far the commonest reserve material in seeds, and 
grains differ in shape according to the kind of seed, so that the 
adulteration of flour, &c., can be detected by means of the 
microscope. 
Fruits are seed-containing structures resulting from a growth 
of the ovary, and sometimes other parts, which follows fertiliza- 
tion. ‘The terms superior, inferior, apocarpous, and syncarpous, 
are used here in the same sense as when dealing with the pistil 
(pp. 100, tor). A distinction is made between (1.) true fruits, 
developed from ovary alone, and (2.) spurious or false fruits 
( pseudocarps), which involve other structures as well. 
I. Spurious Fruits.—These necessarily consist of one or more 
true fruits or developed ovaries surrounded by or imbedded in 
other structures. An entire flower cluster sometimes gives rise 
to a single fruit, termed in this case multiple or collective. Fig, 
pine apple, and mulberry are the commonest examples. 
The flesh of a fig (fig. 34), for instance, is the succulent 
common receptacle, and the “seeds” within it are the true 
fruits. The term “fruit” does not necessarily imply edibility, 
from a botanical point of view at least. Again, each 
of the little red swellings making up a mulberry (fig. 
55) is simply the calyx of a flower become juicy 
and surrounding a small hard fruit. The pine-apple 
is developed from a spike of small crowded flowers, 
the ovaries and floral receptacles of which have 
fused with bracts and axis into a fleshy mass. Hach 
lozenge-shaped area in the outside corresponds to 
a single flower. Seeds are absent as a result of "Uyfopany 
cultivation. 
Collective fruits are formed in another way in beech and sweet 
chestnut. Here the “nuts” are true fruits, and the prickly husk 
in which they are enclosed is formed by bracts which have en- 
larged and grown over them. 
The best types of spurious fruits formed from a single flower 
