318 PHARMACEUTICAL BOTANY 
or seed leaf consists of two parts: the scutellum which lies next to 
the endosperm, and is an organ of absorption, and the sheathing 
portion which surrounds and protects the rest of the embryo. 
That portion of the cotyledonary sheath which surrounds the 
radicle is called the coleorhtza; that portion surrounding the 
plumule, the coleoptile. 
The embryo contains oil and proteids, but no starch. 
If a similar longitudinal section of a soaked grain be mounted 
in dilute iodine solution, the contents of the aleurone cells will be 
colored yellow indicating their proteid nature, while the starch 
grains will take on a blue to violet coloration. ‘The endosperm 
will be observed taking up most of the room within the seed coat. 
The contents of its cells are not baled out to the embryo until 
after germination begins. Indian Corn is therefore an albuminous 
seed. 
GERMINATION OF THE SEED 
When any viable seed is planted in suitable soil, and furnished 
with oxygen and water and a certain degree of heat, germination 
takes place. The first step in germination is the zmbzbition or 
taking in of water. In the presence of moisture, etc., the seed 
imbibes water and the embryo and endosperm (when present) 
swells. ‘The ferments present within the cells of the embryo and 
endosperm then change the insoluble proteid, starch, and oil to 
soluble materials, which, in the case of Indian Corn, are absorbed 
in solution by the scutellum which bales this nourishment out to 
other parts of the growing embryo, there to be used in part in. 
constructing new tissues, and in part to be consumed by oxidation 
or respiration. The process of respiration or breathing takes 
_ place when the plant takes in oxygen and gives off carbon 
dioxide. The oxygen oxidizes the food materials within the 
tissues with an accompanying release of energy, which is neces- 
sary to life and growth. 
The combined pericarp and spermoderm bursts opposite the 
tip of the radicle, and the radicle, piercing through the cotyle- 
donary sheath, protrudes. The cleft in the coat lengthens to the 
point opposite the tip of the plumule, which also protrudes after 
bursting through the cotyledonary sheath. The radicle, next, 
