go A GRAIN OF BARLEY. 
the plant resides in the embryo, the function of the endosperm 
” 
or ‘‘albumen” being merely that of a storehouse or reservoir 
of nutritive material to supply the young plant with food until 
it is sufficiently developed to gain its own sustenance from the 
air and soil. 
The embryo and endosperm are enclosed in the same 
integuments, but there is no true organic connection between 
the two. One side of the embryo is in very close contact 
with the endosperm, but no vascular bundles or nourishing 
vessels of any kind bind the two together, so that there is no 
difficulty in separating these two essential parts of the grain 
without the rupture of any of the tissues of either. How, 
under these circumstances, the embryo can avail itself of the 
stored up material of the endosperm we shall see later on, 
A microscopical examination of the grain is necessary if we 
wish to study its various parts in greater detail. In order to 
do this we must cut sections of the grain in various 
directions, and of such a degree of thinness that they may be 
examined as transparent objects under high powers. The 
cutting of such sections from the ungerminated grain offers no 
difficulties. It is sufficient to soften it in water for a day or 
two, to embed the grain in paraffin or some other suitable 
medium, and to cut very thin slices with the aid of a sharp 
razor. The sections are then treated with various re-agents and 
staining solutions, and examined in water, or better still in 
glycerine. Such a series of sections is before you on the 
table and can be examined at your leisure later in the 
evening. 
Plate I., Fig. 2, is a sketch representing a_ longitudinal 
section of a barley grain, and you see, at the base of the 
corn, the germ or embryo, em, in which can be distinguished 
the rudimentary buds destined to develop into the stem and 
roots of the young plant. The embryo, as you see, occupies 
only a small portion of the grain, the greater part of which is 
made up of cellular tissue, packed very closely with grains 
of starch. Lying close to the ventral side is the “basal hair” 
