Studies of Selected Spermatophytes. 237 



seed dispersal as birds are. It seems, however, that mice 

 are often deterred from climbing the bushes by the down- 

 ward-pointing prickles, and then eat only those fruits which 

 are accidentally broken off. 



The rose family is one of the most important, since it 

 supplies our best fruits and some of our most beautiful 

 flowers. Write a review of the plants of this family which 

 you have studied, embracing the following points : The dif- 

 ference in size and habit shown by the various genera. The 

 different kinds of leaves. The divers forms and character 

 of the receptacles. The essential similarity of the flowers 

 of the family. 



Astragalus caryocarpus (or other species, and species of other 

 genera in the same family). — Ground Plum. 



Draw a leaf. Is it simple, or palmately or pinnately 

 compound ? Draw an inflorescence showing the position 

 in which the flowers stand with reference to the vertical. 

 Draw the different kinds of petals. The upper petal is 

 called the standard or vexillum ; the two lateral petals are 

 termed the wings or alee ; the two united lower petals con- 

 stitute the keel or carina. When a bee visits one of these 

 flowers, it alights on the wings and keel. Watch a flower 

 at such a time to see what transpires. What occurs after 

 the bee leaves the flower.'' Press down upon the wings 

 and keel with the finger tip or with a pencil and note how 

 stigmas and anthers are exposed. Notice what happens 

 after the pressure is removed. Study the mechanism 

 by which the spring-like action of the wings and keel is 

 brought about. Now write down the different purposes 

 fulfilled by the standard, wings, and keel. Note the posi- 

 tions of anthers and stigmas in bud and in blossoms of 

 different ages. Where is the nectar secreted.'' What 



