The Life of the Fly 



surface and the length, an excellent device for 

 decreasing the friction along the earthy column 

 which has next to be scaled. The hydro- 

 cephalous one resumes her performance more 

 vigorously than ever; she inflates and deflates 

 her frontal knob. The pounded sand rustles 

 down the insect's sides. The legs play but 

 a secondary part. Stretched behind, motion- 

 less, when the piston-stroke is delivered, they 

 furnish a support. As the sand descends, they 

 pile it and nimbly push it back, after which 

 they drag along lifelessly until the next ava- 

 lanche. The head advances each time by a 

 length equal to that of the sand displaced. 

 Each stroke of the frontal swelling means a 

 step forward. In a dry, loose soil, things go 

 pretty fast. A column six inches high is trav- 

 ersed in less than a quarter of an hour. 



As soon as it reaches the surface, the insect, 

 covered with dust, proceeds to make its toilet. 

 It thrusts out the blister of its forehead for the 

 last time and brushes it carefully with its front 

 tarsi. It is important that the little pounding- 

 engine should be carefully dusted before it is 

 taken inside to form a forehead that will open 

 no more: this lest any grit should lodge in the 

 head. The wings are carefully brushed and 



polished; they lose their curved notches; they 



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