BIOLOGY OF HIGHER SEED PLANTS 71 



3. The fruit and seed in members of the pea family. 



a. Examine the fruit of the pea, beau, locust, or some 



other member of the pea family. Compare this fruit 

 with that of the pistil already studied. Note the 

 corresponding parts of fruit and ovary. Be able to 

 define a fruit in terms of the pistil. 



b. Remove one half of the wall (carpel) of the fruit and 



observe the form and attachment of the seeds to the 

 placenta. Sketch the inner view of the fruit or pod 

 with the seeds. Label the parts of your sketch accu- 

 rately, including the parts of the seeds. Use the same 

 terms as those used for the pistil and ovules. 



4. Examine seeds of beans or of the locust. How has the 



ovule changed to form the seed ? What advantages are 

 there in the changes ? Do you find the scar on the seed 

 caused by the breaking off of the funiculus ? Do you 

 find other marks near this latter scar ? Draw an exte- 

 rior view of the seed on the side of the hilum, or scar, 

 caused by the removal of the funiculus. Label accurately. 



5. Cut thin sections from the cut surface of the cotyledon of 



a bean. Stain with iodine. Result ? What is the func- 

 tion of the cotyledons ? What kind of reserve food is 

 most prominent as revealed with iodine ? Draw a portion, 

 of the section (Fig. IS). 



SUPPLEMENTARY STUDY 



Study some assigned flower or flowers with reference to devices 

 for securing cross-pollination. Construct drawings to indicate the 

 particular devices for pollination in the flower or flowers examined. 



