PERPETUATION OF LIVING BEINGS 97 



down ; but in the neighbourhood of towns, the number of 

 cats which prowl about the fields eat up the field mice, 

 and of course the more mice they eat up the less there are 

 to prey upon the larvae of the bees the cats are therefore 

 the INDIRECT HELPERS of the bees.* Coming back a step 

 farther we may say that the old maids are also indirect 

 friends of the humble bees, and indirect enemies of the 

 field mice, as they keep the cats which eat up the latter I 

 This is an illustration somewhat beneath the dignity of the 

 subject, perhaps, but it occurs to me in passing, and with 

 it I .will conclude this lecture. 



* The humble bees, on the other hand, are direct helpers of some 

 plants, such as the heartsease and red clover, which are fertilized by 

 the visits of the bees ; and they are indirect helpers of the numerous 

 insects which are more or less completely supported by the hearts- 

 ease and red clover. 



66 D 



