238 Introduction to Botany. 



path must the insect's proboscis follow in reaching it? 

 Note all devices concerned with the protection of the 

 nectar and pollen. Make a cross diagram of the flower, 

 and in it show accurately how the wings and keel are 

 locked together. Does the form of the calyx seem to have 

 any definite relation to the peculiarities of structure of the 

 other parts .' Compare the flowers of the different genera 

 of the family studied. Compare the different members of 

 this family which you have studied, as to size and habit, 

 forms of leaves, details of floral structure, and character 

 of fruit. What features are common to the family, and 

 in what features do you find the greatest variations .■' 



Oxalis violacea. — Violet Wood Sorrel. 



Draw an entire plant, including the bulb and roots. 

 (Some of the leaves may be omitted.) What term would 

 you apply to the leaves, bulb, and inflorescence .-" Note 

 how the leaflets are folded as they emerge from the bud, 

 and notice the day and night positions of the mature leaf- 

 lets. Look for the two forms of flowers. (Read about 

 dimorphic flowers on page 176.) Make longitudinal dia- 

 grams showing exactly the positions of stamens and styles 

 in the two forms. Note how the petals are wrapped in 

 the bud. At what time of day do the flowers open .' 

 After once opening, do they close and open again .' Note 

 the positions of flowers and leaves in cloudy and stormy 

 weather. What meaning do you attach to their behavior .'' 

 Note the way in which the seeds are ejected from the 

 capsules. Compare Oxalis violacea with Oxalis stricta, or 

 other obtainable species. 



Acer. (Obtainable species.) — Maple. 



Dissect an inflorescence and find how much of it con- 

 stitutes a single flower. Examine inflorescences from dif- 



