STUDY 4. 
LEAVES AND THEIR MODIFICATIONS. 
(A Geranium leaf attached to a small portion of stem is 
desirable material. ) 
A. Type Foliage Leaf. 
1. The leaf stalk (petiole) bears upon its distal end the 
expanded portion (lamina, or blade), also at its 
proximal end two smaller expanded portions 
(stipules). Note the structure, form, and color 
of each. 
2. Note the differences in the under (dorsal) and the 
upper (ventral) surface of the lamina. To what 
are they due? 
3. Study the origin and distribution of the veins of the 
lamina. Use m. Why are they so branching? 
4. With m. observe the distribution and forms of hairs. 
Of what advantage are they ? 
5. Make the necessary drawings to demonstrate the 
results of your study. 
6. By tearing the leaf toward one side the epidermis of 
both surfaces may be obtained. With l.p. and 
h.p. study the form and arrangement of the cells, 
hairs, and stomates. 
7. Study the color and contents of the epidermal cells, 
also the number, form, and color of the guard 
cells of the stomates. 
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