The Life of the Wheat Plant from Seed to Seed. 
83 
The grain of wheat is oval shaped, with a deep furrow on 
the one side, and an oblong wrinkled depression towards the 1 
base of the other side, below which is the scar of the attachment 
to the stalk on which the grain was borne. The top of the 
grain is covered with a number of fine hairs. If the grain is 2 
steeped for a few hours in water, it is easy, with a needle or a 
fine knife, to lay back the skin over the wrinkled depression. 
The minute plant or embryo is then exposed, and is seen to be a 
double cone, terminating below in the first root, and above in 
the first leaf. The two roundish coloured swellings on either 
side of the primary root are the first pair of secondary roots. 
When with a razor or sharp knife we cut a grain longitudinally 3 
along the line of the furrow, the knife passes through the middle 
of the little plant. The first root is seen to be protected by a 
little covering, and a similar envelope encloses the first leaf. 
Within this leaf we can already see one or two more leaves 
crowning the minute stem. A slightly coloured organ, developed 
from the inner side of the little plant, separates it from the 
main body of the grain ; this is called the scutellum. It is 
the medium of communication between the plant and its supply 
of food — the mass of hard white material which forms the bulk 
of the grain. A transverse section through the thickest part of 4 
the grain does not touch the embryo, but exhibits only the 
store of white food. A little lower down we cut across the first 5 
leaf enclosed in its protecting sheath, and the scutellum, whose 
outer surface is applied to the store of food. Still lower down 6 
we get a section of the roots and of the lower part of the scutel- 
lum. With a little care the embryo can be removed from the 
rest of the seed, and its form can be seen. This little plant has 
a delicate structure ; the contents of the cells are in a fluid con- 
dition and it easily dries up. The miller describes the embryo 
as “ yellow, moist and oily.” The wrinkling on the surface of 
the grain is caused by the drying of the underlying embryo. 
When a thin section of the store of food is magnified, it is 7 
seen to be made up of an immense number of many-sided cells. 
The cells are filled with starch in the form of minute granules 8 
of different size. The substance of the walls of the cell has 
the same chemical composition as the starch, being built up of 
the elements of water (oxygen and hydrogen) combined with 
carbon. The smaller granules in the outer series of cells are 
more complex in their structure, containing nitrogen in addi- 
tion to the elements forming starch. Similar granules are 
mixed with the starch in the body of the seed. These are the 
gluien of wheat. . 
The two layers which form the protective coveriijg of the 
grain do not properly belong to the seed. They really repre- 
