374 THE BIOLOGY OF THE PLANT 



the pollen on a slide without a cover-glass 

 and examine with the low power. 

 {d) The gynaecmm, consisting of the pistil. — 



What relation does it bear to the other groups ? 



Is it present in all of the blossoms ? In what 



way does it resemble any of the other parts? 



Draw the gynascium. 



The pistil consists of the following parts 



named from below upwards : 



(1) The ovary, at the base of the pistil. — How 

 much of the pistil does it form? What is 

 its shape? Color? To what is it attached? 

 Open it and notice the seed, with its con- 

 tained ovule. What is its structure? What 

 part of the fruit does the waU of the ovary 

 become ? What part the seed ? What changes 

 in shape, size, color, and structure take place 

 as ripening goes on ? 



(2) The style or stalk of pistil. — What is its 

 position? Shape? Size? Color? Compare 

 with the filament of a stamen. Is the divid- 

 ing line between style and ovary well marked? 

 Why called "style"? What becomes of the 

 style as the fruit ripens ? 



(3) The stigma or top of style. — What is its 

 shape? Size? Color? Of how many parts 

 or lobes does it consist ? Examine the sur- 

 face of a mature stigma for pollen grains. 

 What holds them in place? How do they 

 get from- the anther to the stigma? Why 

 named " stigma " ? 



Compare with this flower others taken from the 

 apple or pear tree, bean or pea, violet or pansy, 

 buttercup and the dandelion, noticing especially 



