The Foamy Cicadella 



remarkably persistent even when the insect 

 is not working at it any longer. Deprived 

 of its manufacturer, who would not fail to 

 keep it going, and placed on a watch-glass, it 

 lasts for more than twenty-four hours with- 

 out evaporating or losing its bubbles. This 

 persistency is striking, compared with the 

 rapidity with which soapsuds, for instance, 

 disappear. 



Prolonged duration of the foam is neces- 

 sary to the Cicadella, who would exhaust 

 herself in the constant renewal of her pro- 

 ducts if her work were ordinary froth. Once 

 the effervescent covering is obtained, it is 

 essential that the insect should rest for a 

 time, with no other task than to drink its fill 

 and grow. And so the moisture converted 

 into froth possesses a certain stickiness, con- 

 ducive to longevity. It is slightly oily and 

 trickles under one's finger like a weak solu- 

 tion of gum. 



The bubbles are small and even, being all 

 of the same dimensions. You can see that 

 they have been scrupulously gauged, one by 

 one ; you suspect the presence of a graduated 

 tube. Like our chemists and druggists, the 

 insect must have its drop-measures. 



A single Cicadella is usually crouching in- 



429 



