10 
LABORATORY EXERCISES 
2. Soaked Kernel. Compare the soaked kernel with the dry 
kernel in size and in general appearance. Note the change in the 
“ dent.’’ Explain. Cut the kernel lengthwise and, using a lens, 
note the spongy, shield-shaped portion within. This is the scutel- 
lum or cotyledon. On the cut surface of the spongy portion two 
tiny points appear — the plumule, pointing toward the “ dent ” 
end, and the radicle, pointing toward the sharp end. Note the 
sheaths which cover each point. The scutellum, the plumule, the 
radicle, and the sheaths constitute the embryo. The structure 
which almost surrounds the embryo is the endosperm. Note the 
origin of the horny and the starchy portions of the endosperm. 
What is the origin of the endosperm? Of what use is it to the 
growing plant? Make drawings of longitudinal and cross sections. 
III. What is a seed? 
EXERCISE 11 
CORN AND BEAN SEEDLINGS 
Begin preparations for this exercise 15 days before the seedlings 
are to be used. Make five plantings of corn and five of beans, 
allowing three days to elapse between each planting. LTse seeds 
of the same variety as those which were used in the previous 
exercise. Provide boxes of sand for this purpose. So place these 
boxes that sufficient heat and moisture may be supplied and fre¬ 
quent observations may be possible. Appoint individuals or com¬ 
mittees to assist in or to assume full responsibility for one or more 
plantings and the care of each. When ready for the final exercise, 
remove the seedlings from the sand and prepare exhibits of the 
various stages of growth. This may be done by placing one speci¬ 
men from each stage upon a large card in the order of development. 
I. Development of Bean Seedling. You will make five draw¬ 
ings. Place the first four on one page and allow a full page for 
No. 5. Label drawings, showing from what seed structure each 
part is developed. Study the questions below before making the 
drawings. 
