INSECTS. 285 
ance they are said to be in the jpseudimago state, and to 
them the name duns is applied by the fly-fisher ; when 
they change to the imago or perfect fly, they are called 
piscatorially spinners. There are exceptions to this uni- 
formity, as with the May-flies ; the green drake is the 
pseudimagOj and the grey drake the imago. 
The johryganidce and ephemeridce are easily distin- 
guished ; in the former the wings lie close along the 
back, projecting beyond the body; the antennae or 
feelers are long, and there are no whisks ; in the latter 
the wings stand upright from the body like a butterfly's, 
the antennas are very short, and there are two, or occa- 
sionally three, long delicate whisks. 
The jphryganidce attach their eggs to the foliage over- 
hanging the water, whence upon hatching the larvae fall, 
and immediately proceed to* construct, of twigs or gravel, 
miniature houses like a snail's shell, where they reside in 
peace and safety. These cases are lined with silk, spun 
from the insect's mouth, and are so light as not seriously 
to impede its swimming and rambling in search of food, 
and being open at both ends, allow him a view of the 
outside world. The larvae live mainly on aquatic plants, 
and when the proper time arrives, they close the ends of 
their houses with a species of grating, and commence the 
dormant state of the pupa. In this they remain a few 
days, and then emerging from their case, they ascend to 
the surface, burst their skin, and fly away in their perfect 
state of beauty. 
Tlie e^hem^eridcB deposit their eggs in the water, where 
they soon hatch, and where the grub, which lives usually 
on clay or vegetable matter, resides, occasionally for 
