-8 FOUNDATIONS OF BOTANY 
Note the cavity in each cotyledon caused $54 the pressure of the 
plumule and of the hypocotyl. 
~ 4, Examination of the Pea. — There are no very important points 
of difference between the bean and pea, so far as the structure of 
the seed is concerned, but the student should rapidly dissect a few 
soaked peas to get an idea of the appearance of the parts, since he 
is to study the germination of peas in some detail. 
Make only one sketch, that of the hypocotyl as seen in aa 
after the removal of the seed-coats.} 
’ 5. Germination of the Bean or the White Lupine, the Pea, and the 
Grain of Corn.—Soak some beans or lupine seeds as directed in 
Section 3, plant them,? and make a series of sketches on the same 
general plan as those in Fig. 9. 
Follow the same directions with some peas and some corn. In the 
case of the corn, make six or more sketches at various stages to illus- 
trate the growth of the plumule and the formation of roots; first a 
main root from the base of the hypocotyl, then others more slender 
from the same region, and later on still others from points higher 
up on the stem (see Fig. 15). The student may be able to dis- 
cover what becomes of the large outer part of the embryo. This is 
really the single cotyledon of the corn (Fig. 6). It does not as a 
whole rise above ground, but most of it remains in the buried grain, 
and acts as a digesting and absorbing organ through which the 
endosperm or food stored outside of. the embryo is transferred into 
the growing plant, as fast as it can be made liquid for that purpose. 
- 6. Germination of the Horse-Chestnut. — Plant some seeds of the 
horse-chestnut or the buckeye, study their mode of germination, and 
observe the nature and peculiar modifications of the parts. 
Consult Gray’s Structural Botany, Vol. I, pp. 19, 20. 
-%. Conditions Requisite for Germination. — When we 
try to enumerate the external conditions which can affect | 
'1 The teacher will find excellent sketches of most of the germinating seeds 
described in the present chapter in Miss Newell’s Outlines of Lessons in 
Botany, Part I. 
‘2The pupil may economize space by planting the new seeds in boxes 
from which part of the earlier planted seeds have been dug up for use in 
sketching, etc. 
