THE SEED AND ITS GERMINATION. af 
which are not too thick to become useful leaves, and so the 
plant is in no special haste to get ready any other leaves. 
The plumule, therefore, cannot be found with the magnifying 
glass in the unsprouted seed, and is almost microscopic in 
size at the time when the caulicle begins to show outside of 
the seed-coats. 
In the bean and pea, on the other hand, since the cotyle- 
dons cannot serve as leaves, the later leaves must be pushed 
forward rapidly. In the bean the first pair are already well 
formed in the seed. In the pea they cannot be clearly made 
out, since the young plant forms several scales on its stem 
before it produces any full-sized leaves, and the embryo 
contains only caulicle, cotyledons, and a sort of knobbed 
plumule, well developed in point of size, representing the 
lower scaly part of the stem. 
