The so-called psyche or butterfly is generated from caterpillars
which grow on green leaves, chiefly leaves of the raphanus, which some
call crambe or cabbage. At first it is less than a grain of millet; it
then grows into a small grub; and in three days it is a tiny
caterpillar. After this it grows on and on, and becomes quiescent
and changes its shape, and is now called a chrysalis. The outer
shell is hard, and the chrysalis moves if you touch it. It attaches
itself by cobweb-like filaments, and is unfurnished with mouth or
any other apparent organ. After a little while the outer covering
bursts asunder, and out flies the winged creature that we call the
psyche or butterfly. At first, when it is a caterpillar, it feeds
and ejects excrement; but when it turns into the chrysalis it
neither feeds nor ejects excrement.