INSECTS AND FLOWERS 18; 



insects visit the flowers and obtain the honey 

 and pollen from them. Let us on a warm 

 spring morning enter a copse in search of 

 Primroses. The fragrance of the delicate yellow 

 blossoms is carried to us on the gentle breeze, 

 and everywhere we hear the busy hum of insect 

 life. Perhaps as we gather our nosegay, there 

 comes back to us the happy memory of a similar 

 excursion made in our childhood days, and of 

 how we sought for the two kinds of Primrose 

 blossoms which we called respectively pin-eyed 

 and thrum-eyed Primroses. Seeking them once 

 more, we quickly realize that the two types of 

 blossom are never to be found on one plant, 

 but that each bears but one form of flower. In 

 the pin-eyed flower, only the little round stigma 

 is visible at the top of the tube, the stamens 

 being hidden halfway down inside the flower- 

 tube. In the thrum-eyed blossom, on the other 

 hand, only the stamens are visible at the top of 

 the corolla-tube ; while the short-styled stigma 

 only reaches to the same position as the stamens 

 in the pin-eyed flower. 



Now as we examine these two types of 

 flowers, the fact is born in on us that while the 

 pollen from the stamens of a thrum-eyed Prim- 

 rose might fall down the tube and lodge upon 

 the short-styled stigma within, it is obvious that 

 the pollen from the stamens of a pin-eyed flower 

 cannot get up to the top of the tube on to the 

 long-styled stigma. How, then, does the pin- 

 eyed flower become fertilized? Let us watch 

 the bees closely as they visit the flowers, and 

 see if we cannot find out for ourselves the 



