PLANT CELLS 15 



Find a melon vine, or, some time before it is needed, plant 

 some seeds of this vegetable in a pot and allow the plants 

 to grow a foot or more in length. Collect a quantity of a 

 moss that has thin, flat leaves, and keep it in a moist jar 

 until wanted. 



A. Mount a bit of the pond scum in water on a glass slide 

 and cover with a cover glass. Examine with the low power 

 () objective. 



What is the color of the plant ? Of what does the plant, as 

 a whole, consist ? What are the structural units of a single 

 thread ? What is the shape of each cell ? Note the spiral 

 band in each cell. Are the cells longer than they are wide ? 



Make drawings showing the threads and the cells. Make 

 notes on the color, appearance, and habitat of the plant. 



B. Mount a leaf of the moss. Note the shape of the leaf 

 and the midrib. Note that the leaf is made up of cells. 

 Note that the cells are of various sizes and shapes. What 

 is contained within them ? Do they possess walls ? 



Make a drawing of the whole leaf and then of a half 

 dozen cells much enlarged. 



C. Examine the melon vine, and note the fuzzy ap- 

 pearance of the stems. What causes it? Carefully 

 scrape off some of the hairs with a sharp scalpel or knife 

 and mount them on a glass slide in water. Examine with 

 the low-power objective, and note the shape and structure 

 of each hair. What is the shape of each cell ? Note that 

 the cells are joined end to end. 



Make a drawing of a hair showing its structure. 



With the high-power objective watch closely for some 

 length of time a single cell. Is the wall of the cell opaque 

 or transparent? What is inside of the cell? Note a 

 light, circular spot, the nucleus, usually at one side of the 



