200 INSECTS AND MAN 



pollen from variety to variety, and sometimes from species 

 to species, but never from order to order, and they never 

 return to their hives from a foraging expedition with 

 different varieties of pollen on their bodies. Where other 

 insects visit a single flower, bees will visit a hundred ; and 

 this is important, for flowers mature rapidly, and the 

 vitality of pollen is short-lived. Again, when other insects 

 carry pollen it is entirely accidental ; but bees cannot live 

 without it ; their young cannot be nursed to maturity with- 

 out it ; they are the only insects having instruments and 

 appliances for gathering, carrying, and storing pollen. 

 Every movement of bees in the direction of fertilisation is 

 a studied one, designed by nature to accomplish the per- 

 petuation of the plants they are at work upon. The 

 anthers of some flowers are so situated as to discharge the 

 pollen only on some particular spot of the external anatomy 

 of the bee, and the stigma is so placed in the flower that 

 only the portion of the bee that has received the pollen 

 would be capable of effecting the purpose. 



Only honey bees and humble bees are furnished with 

 apparatus suitable for collecting and carrying pollen from 

 flowers of any and every form or design. The mason and 

 leaf-cutter bees, Osmia and Megachile, are adapted for 

 fertilising broad, flat flowers with protuberant reproductive 

 organs, because the undersides of their abdomens are 

 furnished with long stiff hairs, pointing the " wrong way," 

 which brush the pollen from the anthers. The hairs on the 

 hinder legs of humble bees are distributed in an irregular 

 fashion and are fairly efficient as pollen gatherers ; but, in 

 the honey bees, the hairs are arranged in eight or nine 

 regular rows, and this regular arrangement enables them to 

 brush the pollen from the anthers far more effectively than 

 is the case with any other species. Most of this pollen is, 

 of course, transferred to the pollen baskets, but many grains 

 escape, and it is these grains that bring about fertilisation. 



Let us consider, for a moment, how well adapted the 



