THE SOCIAL INSECTS 



has recently analysed much of this behaviour by marking 

 individual bees and watching what they do when collecting 

 pollen or nectar. Some flowers, such as buckwheat, secrete 

 nectar mainly at a particular time of the day ; the bees which 

 visit it may restrict their foraging to this period, apparently 

 spending the rest of their time inside the hive. By exposing 

 dishes of syrup at particular times of the day it has been 

 shown that the foragers have quite an accurate time-sense 

 and can be trained to come for it at a particular hour. When 

 the nectar is brought in it is handed over to a home bee which 

 spends some minutes in concentrating it by sucking it in and 

 out over the surface of the tongue before storing it in one 

 of the cells. 



Pollen is just as important to the bees as nectar, since it is 

 their source of protein. Without it, the life of the workers 

 is very much shortened and the brood cannot be reared. A 

 considerable store of pollen is always kept through the 

 winter, and this makes it possible for brood-rearing to begin 

 early in the spring when fresh pollen is relatively scarce. A 

 small quantity of honey is added to the stored pollen ; this 

 mixture is " bee-bread ", and it has good keeping qualities. 



Propolis is made from resin collected from various plants, 

 especially trees. It is used to stop up any small crevice in 

 the hive and to cover up objects which are too large to be 

 removed. Some varieties of bees collect much more of it 

 than others do. Balm is a particular variety of propolis, 

 more liquid and transparent than usual. There is some doubt 

 whether it is collected from particular sources of resin or 

 whether it is secreted by the bees themselves. It is used to 

 varnish the inside of the cells before eggs are laid in them. 



Water is collected in quite large quantities, especially in 

 hotter, drier climates. It is apparently used both to cool the 

 hive by evaporation and to prevent the interior of the hive 



no 



