A MANUAL OF BOTANY 71 



tongue to the sap. What is the taste ? Of what special 

 use may this latex be ? What is the inflorescence ? 



Flower. Study a single flower. What is the number and 

 color of the sepals and petals ? Test the flower for odor. 

 Is it pleasant? Within the petals and attached to them 

 notice a corona of five concave hoods, each bearing within 

 a Closed horn. Observe the stamens and determine their 

 number and place of origin and the short filaments and 

 anthers. How are these related to each other and to the 

 stigma ? Notice a peculiar inflexed. membranous tip to 

 each anther. Seek carefully for the pollen 7nasses and ob- 

 serve, if possible, the peculiarity of their attachment. 



Draw a flower plan, a flower, and details of the corona and 

 stamens. 



Action toward insects. In your reference books read about 

 the relation of these plants and bees. Notice in summer the 

 charm the common milkweed flowers have for butterflies. 

 What attracts them ? What do you find, occasionally, has 

 happened to insects ? May the flower be said to have be- 

 come too highly specialized when it catches insects ? 



Latex. Make a list of all the plants you know that have 

 milky sap or latex. 



Collect a lot" of milkweed " sap," heat it slowly and care- 

 fully over a smoky fire. What happens ? Put your heated 

 product aside to cool. Examine and test for odor, color, 

 consistency, and toughness or elastic qualities. 



What plants furnish rubber ? How is it prepared ? 

 Why is it valuable? Burn a piece and observe all the 

 phenomena. Put a small piece of pure soft rubber into a 

 vial of chloroform. What happens ? Try another piece in 

 bisulphide of carbon. (Keep both away from flame.) 



Make some scars in the fruit capsules of the large garden 

 poppies. Observe the latex and allow it to dry. What 

 color has it ? What have you produced ? (Read about 

 opium.) 



