Studies of Selected Spermatophytes. 235 



all mature at about the same time ? Can self pollination 

 take place spontaneously, or is the aid of insects neces- 

 sary ? Where is the nectary ? What kinds of insect 

 visitors do you find ? Examine flowers of different ages 

 for exudation of nectar. Make a cross section of the 

 ovary. How many cells and how many ovules do you 

 find? Make a longitudinal diagram of a flower. Estimate 

 approximately the percentage of flowers that fall off 

 without forming fruit. How do you account for the 

 facts ? 



Compare a peach flower with that of the plum. In both 

 cases what part of the ovary forms the pulp of the fruit, 

 and what part forms the stone ? What reasons do you see 

 for classifying the plum and peach in the same genus.' 

 Compare the flower and fruit of the apple with that of the 

 plum and peach. What are the reasons for classifying 

 the apple in the same family with the plum and peach, 

 but not in the same genus.' In what details would the 

 plum flower need to be modified to become like the apple 

 flower.' How does the following statement agree with 

 what you are able to observe : The fruit of the apple is 

 composed of the ovary (the core) immersed in and ad- 

 hering to the fleshy receptacle. For comparison make on 

 one page longitudinal diagrams of the flowers and fruits of 

 the peach or plum and apple and point out the correspond- 

 ing parts in flowers and fruits. 



Fragaria Virginiana. — Virginia Strawberry. 



Draw the entire plant. What term would you apply 

 to the underground stem .' What term to the leaves .' 

 Describe the leaflets as to form, margin, texture, etc. 

 Show by drawings how multiplication other than by seeds 

 takes place. Examine a patch of wild strawberries in 



