CHAPTER I. 
THE STRUCTURE AND GERMINATION OF FAMILIAR 
SHEDS. 
1. The Broad-Bean Seed.—If we examine a soaked 
broad-bean seed (fig. 1) we find on the outside a tough 
covering, the seed-coat or TEsTa, which can easily be 
removed. At one side of the seed is a broad scar, the 
Hiuvm, marking the place where the seed was attached 
to the bean pod. At the lower end of this scar is a 
small hole from which a drop of water will exude if the 
seed is squeezed. This hole is called the Micropyne, 
On removing the testa we find that the inside of the 
seed consists of a mass of fleshy material, which can 
easily be split into two lobes. 
Each of these lobes is called a CoTyLEDon (fig. 1 B). 
They are really leaves swollen by the deposition of food 
material. Between the cotyledons are the embryo root 
and stem. The embryo root, called the RapicLz, points 
towards the micropyle; the embryo stem, called the 
PLUMULE, lies between the two cotyledons. 
2. Germination.—If we supply a dry bean seed with 
water, air, and a certain amount of warmth, it becomes 
actively alive, swells, grows, and finally develops into a 
bean plant. The dry bean was alive, but in a dormant 
state. This change of a seed from a dormant state to an 
