On the way they have probably encountered the rootlets of my little plantation.  Did they halt in order to take a little nourishment by implanting their proboscis?  This is hardly probable, for a few rootlets were pressed against the bottom of the glass, but none of my prisoners were feeding.  Perhaps the shock of reversing the pot detached them.

It is obvious that underground there is no other nourishment for them than the sap of roots.  Adult or larva, the Cigale is a strict vegetarian.  As an adult insect it drinks the sap of twigs and branches; as a larva it sucks the sap of roots.  But at what stage does it take the first sip?  That I do not know as yet, but the foregoing experiment seems to show that the newly hatched larva is in greater haste to burrow deep into the soil, so as to obtain shelter from the coming winter, than to station itself at the roots encountered in its passage downwards.

I replace the mass of soil in the vase, and the six exhumed larvae are once more placed on the surface of the soil.  This time they commence to dig at once, and have soon disappeared.  Finally the vase is placed in my study window, where it will be subject to the influences, good and ill, of the outer air.

A month later, at the end of November, I pay the young Cigales a second visit.  They are crouching, isolated at the bottom of the mould.  They do not adhere to the roots; they have not grown; their appearance has not altered.  Such as they were at the beginning of the experiment, such they are now, but rather less active.  Does not this lack of growth during November, the mildest month of winter, prove that no nourishment is taken until the spring?

The young Sitares, which are also very minute, directly they issue from the egg at the entrance of the tubes of the Anthrophorus, remain motionless, assembled in a heap, and pass the whole of the winter in a state of complete abstinence.  The young Cigales apparently behave in a very similar fashion.  Once they have burrowed to such depths as will safeguard them from the frosts they sleep in solitude in their winter quarters, and await the return of spring before piercing some neighbouring root and taking their first repast.

I have tried unsuccessfully to confirm these deductions by observation.  In April I unpotted my plant of thyme for the third time.  I broke up the mould and spread it under the magnifying-glass.  It was like looking for needles in a haystack; but at last I recovered my little Cigales.  They were dead, perhaps of cold, in spite of the bell-glass with which I had covered the pot, or perhaps of starvation, if the thyme was not a suitable food-plant.  I give up the problem as too difficult of solution.

To rear such larvae successfully one would require a deep, extensive bed of earth which would shelter them from the winter cold; and, as I do not know what roots they prefer, a varied vegetation, so that the little creatures could choose according to their taste.  These conditions are by no means impracticable, but how, in the large earthy mass, containing at least a cubic yard of soil, should we recover the atoms I had so much trouble to find in a handful of black soil from the heath?  Moreover, such a laborious search would certainly detach the larva from its root.