26 SECRETS OF ANIMAL LIFE 
power of flying backwards in front of one’s bicycle 
for a quarter of a mile at a time; there is the 
consummate efficiency (incalculably beneficent from 
man’s point of view) in destroying in a great variety 
of ways large numbers of injurious insects—for 
wasps are carnivores and scavengers of big appetite, 
as well as the honey-suckers, fruit-eaters, and jam- 
thieves we all know them to be. 
But, tearing ourselves away from these familiar 
wonders, we wish to direct attention to a quaint 
piece of domestic economy which Dr, Roubaud has 
recently discovered among African wasps. These 
know no winter or interruption in their year, and 
they throw fresh light on species like ours which 
are severely punctuated by northern seasons, For 
it is well known that of the great summer com- 
munity of wasps only the young fertilized queens 
survive the winter. They have sought out sheltered 
nooks, under thatch and the like, where, fixed by 
their jaws, and occupying a position quaintly like 
that which they had as pupe within their cradles, 
they lie asleep till the spring. 
Among bees and wasps there has been social 
evolution on a primarily instinctive and secondarily 
intelligent basis—rookeries and the like being on 
a primarily intelligent and secondarily instinctive 
basis; our evolution being on a vaguely instinctive, 
primarily intelligent, and occasionally rational 
basis. There are many solitary wasps and solitary 
bees, and there are many grades of sociality, or 
whatever it be called, between the solitary life and 
