264 NATURAL HISTORY. 
‘rises by the stream of fire at its end. Another purpose 
is accomplished, also, by this operation. The breathing 
apparatus is in this quarter of the body, the air in the 
water being there introduced to the blood of the insect, 
just as it is introduced to the blood of the fish in its gills. 
It spends nearly a year in the water, and then comes 
its metamorphosis. This, Jaeger says, “‘may be ob- 
served almost daily from the month of April until Octo- 
ber, but occurs principally in the months of May and 
June. But this transformation does not take place in the 
water, but out of it; and when ready for their metamor- 
phosis, the larve climb up the stem of some water-plant, 
and in about two hours after are capable of raising them- 
selves up by their wings and flying away in the air. This 
whole operation may be witnessed by putting the grubs 
into a pail of water, and placing in it some sticks or 
branches upon which they may creep up and prepare 
themselves for their aerial journeys.” 
452. The Ephemeride, or Day-flies, are so called from 
their short existence in the imago state, which, like that 
of some flowers, is limited to a single day, In their larva 
state, however, they have a long life of two or even three 
years. During this time they are inhabitants of the wa- 
ter, having leaf-like appendages on their sides as their 
gills or respiratory apparatus. When they are about to 
change to the imago state, wings are formed, but are kept 
folded up till they are ready to leave the water. While 
these are forming the insect is said to be in the pupa or 
chrysalis state, and yet it is as active now as when it was 
alarva. The escape of the insect into the air is so quick- 
ly done, that it seems as if it flew directly out of the wa- 
ter. It casts off its skin as readily as a man puts off a 
coat, unfolds its wings, and, with its feet resting on its 
cast-off skin, it takes its flight. 
453. These insects are sometimes produced in such 
multitudes that the ground is covered with their dead 
bodies, and they are carted away as manure. Professor 
