MANUAL OF NATURE} STUDY. 
91 
Show that the material absorbed in solution 
by the roots must be conveyed to the leaves for 
making into plant substance, and that this solu¬ 
tion is sap. The leaves receive the sap from the 
stem, as raw material. By the action of sunlight 
this raw material and carbon-dioxide are changed 
into plant-substance and distributed to the growing 
parts of the plant. 
Further than this, sap cannot be discussed in 
this grade. 
3. Study of useful roots and tubers , as beets , 
potatoes , etc—a. Form. b. Structure, c. Uses. 
This topic has been sufficiently covered in (2) of 
this course. 
4. Study of grains and grasses , as wheat , corn , 
oats , timothy , clover , etc .— a. Harvesting, b. Mar¬ 
keting. c . Commercial value. 
Unfortunately, it is difficult to obtain material of 
growing wheat, oats and timothy during school year. 
If possible to bring these to maturity by plant¬ 
ing in boxes, do so, and consider them all at the 
same time. 
Points to be observed: 
1. Kind of stem, whether hollow or pithy. 
2. Examine the nodes to see if the hollow, or 
pith, continues throughout the entire length of the 
stalk, 
