232 Introduction to Botany. 



Answer from observation the following questions : How is 

 the pollen protected? Where is the nectar secreted and 

 stored up ? How is the nectar protected from the rain ? 

 To what sorts of insects is the nectar accessible ? Do the 

 anthers all discharge their pollen at the same time ? What 

 positions do the anthers assume before and after discharg- 

 ing their pollen ? Do the anthers and stigmas of a flower 

 mature at the same time, or does the flower afford an ex- 

 ample of proterandry or proterogyny ? Do the styles and 

 stigmas assume different positions at different ages of the 

 flower ? Now make three longitudinal diagrams, one of a 

 newly opened flower, one of a middle-aged flower, and one 

 of a fading flower, showing the different positions of the 

 stamens and styles. Observe the positions of insects in 

 visiting these flowers. Do they proceed from young to 

 older flowers of the inflorescence or vice versa ? What 

 order of procedure would be best to insure cross pollina- 

 tion between flowers of different plants? How long must 

 the insect's proboscis be to reach the bottom of the nectary ? 

 In what ways are these flowers adapted to attract insects ? 



Compare Delphinium with Ranunculus. What similari- 

 ties have they which warrant their classification in the 

 same family ? What dissimilarities compel a classification 

 in different genera ? 



The flower of the larkspur is of peculiar interest on ac- 

 count of the specialization of its parts for definite purposes. 

 The changes in the positions of stamens and styles at dif- 

 ferent periods are wonderful exhibitions of the power of 

 movement of plant parts to accomplish specific results. 



Dicentra cucullaria. 



What is the habitat of this plant ? What is *the char- 

 acter of its underground parts ? Why are the leaves called 



