EIGHTH DAY.] EPHEMERAE. 215 



animals fitted for generation ; they make use 

 of their wings only to fly to some dry bank, or 

 trunk of a tree, where they gradually disencumber 

 themselves of the whole of the outward habiliment 

 they brought from the water, including their wings ; 

 they become lighter, more beautiful in colour, and 

 then begin their sports in the snnshine — appear- 

 ing like what might be imagined of spirits freed 

 from the weight of their terrestrial covering. This 

 last transmutation has been observed and fully 

 described by some celebrated naturalists, in the case 

 of the May-flies, and one or two other species, and it 

 probably will be found a general circumstance 

 attached to the class; I have often observed what 

 appeared to me to be the cast-off skins of the small 

 species of ephemerae on the banks of rivers and floating 

 in the water. The green ephemera, or May-fly, lays 

 her eggs sitting on the water, which instantly sink to 

 the bottom ; and most of the duns, or small slender- 

 winged flies, do the same. The gray, or glossy-winged 

 May-fly, commonly called the gray drake, performs 

 regular motions in the air above water, rising and 

 falling, and sitting, as it were, for a moment on the 

 surface, and rising again, at which time she is said to 

 deposit her eggs. To attempt to describe all the 

 variety of ephemerse, that sport on the surface of the 

 water at different times of the day, throughout the 



