The Golden Rule for Flowers 187 



and as the holly grows its stamens and pistils mostly on 

 different plants, the dearth of berries was doubtless owing 

 to the absence of bees. 



For though holly-bloom are insignificant, they are fer- 

 tilized chiefly by bees, and not by wind, pollen having been 

 observed by Mr. Darwin on many pistil-tips, which must 

 have been brought from a tree sixty yards away, and could 

 not have been conveyed by the wind, since it was blowing 

 in the wrong direction. 



The year that the holly-berries failed, the crop of 

 clover-seed failed also in some parts, and no doubt from 

 the same cause. For though some clovers manage to 

 fertilize themselves more or less, there is a very marked 

 difference in the quantity of seed borne by the plants, 

 according as they are kept covered, and out of the way of 

 insects, or not. 



A hundred heads of common red clover bear about two 

 thousand seven hundred and twenty seeds among them; 

 but a hundred heads covered with a net on one occasion, 

 to keep off the bees, had not one single seed. This com- 

 mon red clover has a tube, too long to be sucked by the 

 hive-bee until it has been mown, when the second crop of 

 blossoms are said to be rather smaller, and its first crop 

 is dependent on the humble-bee. A very slight difference 

 in length makes just all the difference as to the species of 

 bee which is able to extract nectar from the blossom. 

 The brilliant crimson clover is frequented by the hive-bee, 

 its tube being shorter than that of the common red kind. 



Strawberry plants are altogether dependent upon bees 

 for the perfecting of their fruit, even where pollen and 

 ovules are produced in the same blossoms. In one 

 species of strawberry, the true hautbois, they are borne 



