116 SECRETS OF ANIMAL LIFE 
community to evade the terrific autumnal elimina- 
tion seen in ordinary wasps and humble-bees. The 
activities in the hive sink to a minimum, it is true, 
but the point is that the community lasts, and in a 
favorable year should not, after yielding much 
honey to their owner, require any winter feeding 
from him if he is not too greedy in what he exacts. 
But every one knows that there is autumnal 
tragedy in the beehive too, for some time after 
the queen has been fertilized the workers unite 
to destroy the now useless drones, either murder- 
ing them directly or driving them forth to 
perish. 
Deeper than the particular problems of the natural 
history of autumn is the general biological problem 
of what it all means, and the answer is that the 
seasons are externally instituted periodicities to 
which organisms have had to adapt themselves. 
But it is not merely that living creatures have be- 
come in a self-preservative way fitted to cope with 
or circumvent the difficulties of the seasons; they 
have also evolved subtle tactics which have made 
use of the difficulties as opportunities for advance. 
Just as the alternation of hard work and quiet rest, 
physiologically natural in higher animals, fits in well 
with the alternation of day and night, so rhythms 
of longer period fit in well with the periodicities of 
the seasons. It cannot be said that the alterna- 
ticn of work and rest, including, for instance, the 
“loading” and “ unloading ” of internal glands, is 
the direct and necessary result of the alternation of 
