306 MOTIONS OF INSECTS. 



they seem to walk upon stilts ; but when we consider 

 that they have to walk over and amongst grass, — the 

 former laying its eggs in meadows, — we shall see the 

 reason of this conformation. Insects do not always 

 walk in a right line ; for I have often observed the little 

 midges {Psychoda, Latr.), when walking up glass, moving 

 alternately from right to left and from left to right, as 

 humble-bees fly, so as to describe small zigzags. 



Numerous are the insects that run. Almost all the 

 predaceous tribes, the black dors, clocks, or ground- 

 beetles {Eutrech'ma), and their fellow destroyers the Ci- 

 cmdelce, and other Eu2)ter\na — which Linne, with much 

 propriety, has denominated the tigers of the insect world, 

 — are gifted with uncommon powers of motion, and run 

 with great rapidity. The velocity, in this respect, of 

 ants is also very great. — Mr. Delisle observed a fly — so 

 minute as to be almost invisible — which ran nearly three 

 inches in a demi-second, and in that space made 54<0 

 steps. Consequently it could take a thousand steps 

 during one pulsation of the blood of a man in health ». 

 Which is as if a man, whose steps measured two feet, 

 should run at the incredible rate of more than twenty 

 miles in a minute ! How astonishing then are the powers 

 with which these little beings are gifted ! — The forest-fly 

 {Hippohosca), and its kindred genus OrnWiomyia pa- 

 rasitic upon birds, are extremely difficult to take, as I 

 have more than once experienced, from their extreme 

 agility. 1 lost one from this circumstance two years 

 ago that I found upon the sea-lark [Charadrius Hiati- 

 cula) and whicii appeared to be non-descript. Another 

 most singular insect, which though apterous is nearly 

 " Lesser, L. i. 248, note 24. • 



