A 71 Unknown Sense 353 



difficulties which this breeding would present. 

 We have not to do with the Bee, who is faithful 

 to her hive, because of her social habits ; still 

 less with the stupid Silkworm, perched on its 

 mulberry-leaf, or its clumsy Moth, who for a 

 moment flutters her wings, pairs, lays her eggs 

 and dies : we have to do with an insect that is 

 capricious in its wanderings, swift of flight and 

 independent in its ways. 



Besides, the first condition shatters all our 

 hopes. Would we have the helpful Ammo- 

 phila ? Then we must resign ourselves to 

 accepting the Grey Worm. We move in a 

 vicious circle : to produce good we must invoke 

 the aid of evil. The hostile band brings the 

 friendly troop to our fields ; but the second 

 cannot live without the first ; and the two 

 show an even balance in numbers. If the Grey 

 Worm abound, the Ammophila finds copious 

 provender for her grubs and her race prospers ; 

 if the Grey Worm be rare, the Ammophila's 

 offspring decrease and disappear. This balance 

 between prosperity and decadence is the immut- 

 able law that governs the proportions between 

 devourers and devoured. 



