LABORATORY AND FIELD WORK 393 



13. Examine a full-grown leaf from an older plant. What is 

 its shape ? What are the parts of the leaf ? What differences do 

 you find between the upper and lower surfaces ? Study the veins 

 and the way in which they branch. Notice that they form a fine 

 network. Study the hairs with a hand lens. On what parts of 

 the leaf do you find them ? On what parts are they most numer- 

 ous ? Where are the largest hairs borne ? 



14. What is the shape of the stem ? Is it solid or hollow ? How 

 are the leaves arranged on it? Can you find a bud in the axil of 

 each leaf ? Where are the branches attached to the stem ? Where 

 are the tendrils attached ? 



15. Draw a portion of the stem and two successive leaves at- 

 tached to it, with the axillary buds. Show the veins in one leaf. 



16. Examine the bud at the end of the main stem or of a branch. 

 Tear it apart carefully. Of what parts do you find it composed? 

 How many young leaves do you find in it ? 



17. Remove the parts, one by one, from a pistillate flower ; from 

 a staminate flower. Draw the circle of sepals so removed, cut in 

 one place and spread out flat ; draw the circle of petals in the 

 same way ; a pistU, naming the parts ; a stamen, naming the parts. 



18. Follow from day to day the development of the ovary into 

 a fruit. Cut a ripe or nearly ripe fruit crosswise and draw one 

 of the cut surfaces, naming the parts. 



19. Make a list of the different varieties of cucumber and of 

 squash grown in your locality. What are the important points of 

 difference between them? What particular advantage has each 

 variety, and for what special uses is it best suited ? 



Chapter II 



1. Place some hay in a dish of lukewarm water, cover it, and 

 put it in a warm place. After two or three days examine a very 

 small drop of the water under the high power of the microscope. 

 It will be found to contain a great many organisms of different 

 sorts, among thehi some having the shape of short rods with rounded 

 ends. Most of these are probably cells of Bacillus subtilis. Are 

 they colored? Some are swimming actively, others are quiet. 

 Describe their movement. 



