I INTRODUCTION 7 
and even then the work of collecting it would be 
laborious. 
The tongue of the humble-bee is much longer 
than that of the honey-bee, consequently she can 
extract honey from flowers having long narrow 
tubes, such as red clover, honeysuckle, and hore- 
hound, which are seldom or never visited by 
honey-bees. As a rule these flowers are very 
melliferous. Indeed, the heads of the red clover 
contain more honey than almost any other flower, a 
fact appreciated by children, who pull out the tubes 
and suck them. Humble-bees have almost a mono- 
poly of the vast amount of. honey that is produced 
in a red clover field, but there are not enough of 
them to gather much of it. 
Nevertheless humble-bees are extremely valu- 
able for fertilising the numerous flowers that they 
frequent. Whole groups of plants bearing long- 
tubed flowers, including many species valuable to 
man, depend chiefly upon humble-bees for their 
propagation. Charles Darwin, in the Ovigin of 
Species, said: “1 find from experiment that humble- 
bees are almost indispensable to the fertilisation of 
the heartsease (Vzola tricolor), for other bees do not 
visit this flower.” In consequence of the absence 
of humble-bees in New Zealand it was found that 
the red clover did not produce seed freely. So 
in November and December 1884 a number of 
queens were sent from England to that country, 
with the result that two species, B. ¢errestris and 
B. ruderatus, have become established there, and 
