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 \vhich 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- 

 tion of work and rest, including, for instance, the 

 " loading " and " unloading " of internal glands, is 

 the direct and necessary result of the alternation of 



