the larva of danger. It withdraws its proboscis in order to retreat
along its galleries, and when the spade uncovers it has ceased to feed.

If the hazards of field-work, with its inevitable disturbance of the
larvæ, cannot teach us anything of their subterranean habits, we can at
least learn something of the duration of the larval stage. Some obliging
farmers, who were making some deep excavations in March, were good
enough to collect for me all the larvæ, large and small, unearthed in
the course of their labour. The total collection amounted to several
hundreds. They were divided, by very clearly marked differences of size,
into three categories: the large larvæ, with rudiments of wings, such as
those larvæ caught upon leaving the earth possess; the medium-sized, and
the small. Each of these stages must correspond to a different age. To
these we may add the larvæ produced by the last hatching of eggs,
creatures too minute to be noticed by my rustic helpers, and we obtain
four years as the probable term of the larvæ underground.

The length of their aerial existence is more easily computed. I hear the
first Cigales about the summer solstice. A month later the orchestra has
attained its full power. A very few late singers execute their feeble
solos until the middle of September. This is the end of the concert. As
all the larvæ do not issue from the ground at the same time, it is
evident that the singers of September are not contemporary with those
that began to sing at the solstice. Taking the average between these two
dates, we get five weeks as the probable duration of the Cigales' life
on earth.

Four years of hard labour underground, and a month of feasting in the
sun; such is the life of the Cigale. Do not let us again reproach the
adult insect with his triumphant delirium. For four years, in the