DISEASES OF WHEAT. 
155 
If the transformation which the seed of wheat undergoes by the formation of brand be 
examined, we find that the particles have undergone either an entire or partial transfor¬ 
mation in respect to internal structure; and without here entering on the technological 
signification of the several parts of the seed, I shall describe the same, in a way generally 
intelligible, and simply, as should always be done, and so pass over the head as well as 
the pistil, since they suffer no visible change by the formation of the brand. The same 
is true of the glumes and petals, the anthers and the spike of the ears themselves. 
The fruit or seed of the wheat viewed on the outside, consists of an elongated irregularly 
egg-shaped body (fig. 16, f) , having on the front surface a streak or furrow lengthwise, 
(fig. 16, k) , which bears on the point the pistil (fig. 16, i) , and the head (fig. 16, h) . 
At the bottom, we see on the back the little shield (fig. 15) containing the germ, and 
the front side the little opening, Feusterchen (fig. 16, g). If the seed is cut across 
through the middle (fig. 18), we find that it has an outer skin (fig. 18, /), which by 
bending inward forms the furrow lengthwise (/c). Inside of this skin are found white 
hard transparent bodies containing starch-meal, which natural historians call the albumi¬ 
nous bodies, “ the albumen” of the seed (fig. 18, m) . If now we cut off as thin as possible 
a slice perfectly transparent, in the direction already mentioned, and examine the same 
microscopically, we find that, 
1. The skin of the seed (fig. 18, /) consists of three layers, to wit: 
a. The outer layer (fig. 19, n ) ; 
b. The middle layer (fig. 19, o ) ; and 
c. The inner layer (fig. 19, p ), on which layer immediately lies a large soft cellular 
stratum, which contains the grains of gluten (fig. 19, q ). Nearest the inside lie the amylum 
cells, containing the starch-meal (fig. 19, r, s ). 
a. The outer layer of the seed-skin (fig. 19, n ), consists of two layers of thick-walled 
porous cells, which stand with their longest diameter parallel to the axis of the seed, and 
the walls of which contain slight hollows or little canals, which, in a section cut lengthwise 
and very strongly magnified (fig. 20, w) , give to the cellular walls a form as if they were 
formed of oblong figures. 
b. The second layer (fig. 19, 6) of the seed-skin, consists of similar cells to those of the 
first layer, only the walls of the cells are not so thick ; and the pores, which these walls 
contain are much more distinctly (fig. 19, o ) to be seen, than is the case in the cellular 
walls of the first layer of the skin; but the cells of this layer stand with axis of length 
horizontally to the axis of the first cellular layer and of the seed, and therefore runs as it 
were parallel to the outer surface of the seed. In a section lengthwise they resemble even 
to tjbfe direction of the cells of the first layer of cells, and are nearly as large as they are 
(fig. 20. a:, x) . 
c. The third layer is extremely soft and somewhat confused. Its cells are so small, that 
we can discern their hollows only indistinctly and in the form of mere streaks (fig. 19, p ). 
2. Directly under this cellular stratum or of the seed-skin in general, we find situated 
(he already mentioned cells of gluten (fig. 19, q ). They are large bag-formed cells, with 
