RED CLOVER. 99 



Biology of flower: If Red Clover is isolated during flowering 

 time, so that no insects can visit the blooms, no seeds will be formed, 

 as it depends upon insects to transport the pollen from one flower to 

 another. Bumble bees, which visit the flowers in order to secure the 

 nectar, are especially active in this transportation. The blossoms 

 of Red Clover are peculiarly sensitive; when a bumble bee in search 

 of honey forces its proboscis down and touches the lower parts of a 

 flower, such a touch, if the flower is fully developed, makes the sta- 

 mens and pistil protrude from the interior of the blossom into the 

 open air. The bending of the stamens and pistil brings their upper 

 ends into close contact with the body of the insect, which thus be- 

 comes powdered with pollen from the stamens. The pistil protrudes 

 a little beyond the stamens. This might seem an insignificant fact, 

 but it means that the pistil has a better chance to come in contact 

 with the pollen from other plants, already deposited on the body of 

 the insect, than to come in contact with the pollen of its own flower. 

 As the insect travels from one plant to another, carrying pollen from 

 different individuals, the pistils of one are apt to be fertilized by 

 pollen from another. Such cross-fertilization must, in fact, take 

 place before seed can be developed. In other words, Red Clover is 

 completely self-sterile. The pollen is unable to fertilize the pistils of 

 the plant on which it is produced. 



As a rule, the insect carries enough pollen from different in- 

 dividuals to give the pistils an opportunity to be powdered from other 

 plants. There is, however, a chance that a single visit from one 

 insect would be insufficient. To provide a greater opportunity for 

 every flower to be fertilized, nature has made it possible to have 

 each Red Clover blossom visited by insects many times. In Alfalfa 

 each flower has only one chance to be fertilized (see page 115), as the 

 stamens and the pistil, after the explosion of the flower, do not 

 return to their original positions. A Red Clover blossom has many 

 chances, as the pistil and stamens protrude for only an instant, after 

 which they move back to their original positions. Their sensibility 

 is not lost after the first visit of an insect; a second or third visit 

 will have the same-effect, and the chances of the pistil being properly 

 fertilized will last as long as it remains in a condition to receive the 

 pollen. 



Bumble bees are the only insects, with the exception of some 

 butterflies, with a proboscis long enough to reach the nectar at the 

 bottom of the flower tube. As is well known by bee-keepers, the 

 ordinary honey bee is not able to gather honey from Red Clover, 

 its proboscis being far too short. In spite of this, however, the ord- 

 inary honey bee is of considerable importance in the fertilization of 



