A FEW OLD FAVORITES 121 



contact with the pollen of an individual flower 

 only after it has passed the pistil, and the protect- 

 ing sheath prevents the deposit of pollen as the 

 insect or bird leaves the flower. Thus it is in- 

 sured that self-fertilization will not take place. 



While the flower is complex in this regard, 

 nothing more is necessary than to study its 

 mechanism attentively, pulling to pieces two or 

 three blossoms to see just how the pollen must be 

 deposited. After that you will experience no 

 difficulty in cross-fertilizing the iris, and the re- 

 sults of your work are sure to be of interest. 



FOUR-O'CLOCK AND COLUMBINE 



The familiar four-o'clocks are all natives of 

 America, but most of them had their original 

 home in the subtropical and tropical portions of 

 the two American continents. There is one, how- 

 ever, that is native to California, and various 

 species made their way to the gardens even far to 

 the north a century or more ago, and are now 

 grown everywhere. 



The most striking peculiarity of the four- 

 o'clocks (Mirabilis) is their tendency to combine 

 different colors in the same flower in peculiar 

 patterns. 



We have seen a great deal of color variation 

 among flowers. We have seen numberless in- 



