DECEMBER. 



served them j and I suppose, as a fall of snow took place 

 during the ensuing night, most of those which remained active 

 retired on that day. A few insects, however, are still to be 

 met with ; I found a living Case-fly (Phryganea) on the 

 surface of that snow I have mentioned, on the morning after 

 it had fallen, and small Muscce and Tipulce still fly about 

 the woods, and in sheltered situations. 



C, Here are some hopping atoms, on the surface of the 

 snow on the road side. I observe they are a minute species 

 of Springtail, of a dark bluish grey colour. 



F. This tribe of insects, the Springtails (Podura)> 

 minute and insignificant as they appear, have not been too 

 mean to be the exclusive object of one instance of the in- 

 ventive wisdom of the Deity. These little creatures have a 

 mode of progression peculiarly their own, and differing widely 

 from that of any other animal I know of. The tail termi- 

 nates in two setae, or bristles, which are usually bent up 

 under the belly, but when the insect wishes to move, these 

 fly out straight, and by the elastic force, throw the insect 

 forward by a vast leap. Whether the spring is kept bent by 

 muscular effort, and flies out of itself when relaxed, or whe- 

 ther its natural and unconstrained position is bent, and it is 

 driven out by an exertion, I cannot affirm. It is singular 

 that this species generally appears on the surface of snow, just 

 after it has fallen ; whence coming, I know not. 



C. I have observed several other species : one swarms 

 on little pools of water in summer, sometimes so thickly as 

 completely to hide the water, showing only a surface of black 

 dust, resembling a parcel of gunpowder. Another, a little 

 larger, and lighter in colour, abides in crevices of posts, and 

 particularly of hot -bed frames, in spring. 



F. The different modes by which locomotion is performed, 

 constitute a very curious subject of investigation : they are 

 far more varied than cursory observers would suppose. Some 



