JLLNUTE STKUCTUEE OF LEAVES. 



109 



Examine another slice from the upper surface. 

 How does the number of stomata in the two cases compare ? 

 Take measurements from the last three sketches with a scale and, 

 knowing what magnifying power was used, answer these questions : ^ 

 (a) How thick is the epidermis ? 



(6) "niiat is the length and the breadth of the epidermal ceUs ? 

 (c) ^'hat is the average size of the pulp-cells ? 



Fis. 96. 



*P sp 



- Vertical Section of the Leaf of the Beet. (Much magnified.) 



jf epidermis ; p, palisade cells (and similar elongated cells) ; t, intercellular spaces ; 

 a, air-spaces communicating "with the stomata ; sp, stomata, or hrea thing-pores. 



136. Uses of the Parts Examined. — It will be most con- 

 venient to discuss the uses of the parts of the leaf a little 



^ The teacher may measure the size with the camera Ittcida. 



