REPRODUCTION IN PLANTS 89 



II. THE STRUCTURE AND FUNCTIONS OF FRUITS 



99. Relation of fruits to reproduction. We have already 

 learned that the use or function of flowers is to insure the 

 production of seeds. As is generally known, seeds are found 

 in fruits. We are now to study several types of fruits. 



100. Study of the bean or pea fruit. Laboratory Study 

 No. 46. 



A. Outside of the fruit. 



Study if possible young pods, well-developed pods, and 

 pods that have dried; or charts may be used 

 to show the developing pods. 



1. Name and describe the structure which attached the 



pod to the plant. 



2. The main part of the fruit or pod is the pistil, which 



in the bean or pea flowers consisted of ovary, 

 style, and stigma. Which of these parts are 

 found in the fruit you are studying? (Fig. 35.) 



3. Bean and pea blossoms have calyx, corolla, stamens, 



and pistil. What parts of the flower are present 

 in the fruit? What parts have disappeared? 



4. Make a drawing, natural size, of the fruit you are 



studying in the position in which it hung on the 

 plant. Label fruit-stalk, calyx (if present), and 

 the parts of the pistil that you find. 



B. Inside of the fruit. 



Split the pod lengthwise into halves. 



1. Carefully move one of the seeds in the pod ; is it free 



from the pod, or is it attached ? 



2. (Optional.) The region of an ovary to which seeds are 



attached is called the placenta (as was also the case 

 in the ovary of flowers). Locate the placenta in the 

 fruit you are studying. 



3. (Optional.) State whether or not you find any undeveloped 



seeds. Undeveloped seeds probably never were fer- 

 tilized. 



