LETTER XXIII. 
MOTIONS OF INSECTS. (dmago.) 
11. THE motions of insects in their perfect or zmago 
state are various, and for various purposes; and the pro- 
vision of organs by which they are enabled to effect 
them is equally diversified and wonderful. It will be 
convenient to divide this multifarious subject; I shall 
therefore consider their motions under two principal 
heads :—motions of insects reposing—and motions of in- 
sects 7m action ;—and this last head I shall further sub- 
divide into motions whose object is change of place, and 
sportive motions. 
The first of these, motions of insects reposing, will 
not detain us long. The most remarkable is that of 
the long-legged gnats or crane-flies (Tipule, F.).— 
When at rest upon any wall or ceiling, sometimes stand- 
ing upon four legs, and sometimes upon five, you may 
observe them elevate and depress their body alternately. 
This oscillating movement is produced by the weight 
of their body and the elasticity of their legs, and is con- 
stant and uninterrupted during their repose. Unless it 
