196 INTERNAL ANATOMY OF INSECTS. 



without the flea appearing alarmed 3 . Many caterpillars 

 are accustomed to extend their bodies from a twig, sup- 

 ported merely by the four hind feet, in one fixed attitude, 

 either in an oblique, horizontal, or vertical direction, 

 either upwards or downwards, and that for hours to- 

 gether. We may conceive what prodigious muscular 

 force must be exerted *upon this occasion, by reflecting 

 that the most expert rope-dancer, though endued with 

 the power of grasping with his feet like a bird with its 

 claws, could not maintain himself in a horizontal position 

 even for an instant. Bradley asserts that he has seen a 

 stag-beetle carry a wand half a yard long and half an 

 inch thick, and fly with it several yards 5 . Some insects 

 have the faculty of resisting pressure in a wonderful de- 

 gree. If you take a common dung-chafer (Geotrupes) 

 in your hand and press it with all your strength, you 

 will find with what wonderful force it resists you ; and 

 that you can scarcely overcome the counteraction, and 

 retain the insect in your hand: was it not for this quality, 

 the grub of the gad-fly must be crushed probably in 

 passing through the anal sphincter of the horse c . But 

 that of Eristalis tenax affords a more surprising instance 

 of this power of counteraction: an inhabitant of muddy 

 pools, it has occasionally been taken up with the water 

 used in paper-making, and strange to say, according to 

 Linne, has resisted without injury the immense pressure 

 given to the surrounding pulp d ; like leather-coat Jack 

 mentioned by Mr. Bell e , who, from a similar force of 



a N. Diet. d'Hist. Nat. xxviii. 249. 



* Phil. Ace. of Works of Nat. 144. 



c Clark in Linn. Trans, iii. 309. d Fn. Suec. 1799. 



* Anatomy of Expression in Painting, 170. 



