They are now all clad, my young caterpillars, numbering nearly a thousand. They wander restlessly in large glass receptacles, closed with a sheet of glass. What do you seek, little ones, swinging your pretty, snow-white cloaks as you go? Food, of course. After all that fatigue, you need refreshment. Despite your numbers, you will not be too heavy a burden on my resources: you can manage with so little! But what do you ask for? You certainly do not count on me for your supplies. In the open fields you would have found victuals to your liking much more easily than I can hope to find them for you. Since my wish to know all about you places you in my charge, I have a duty which I must observe: that of feeding you. What do you want? The part of Providence is a very difficult one to play. The purveyor of foodstuffs, thinking of the morrow, taking his precautions so that the home may be always more or less supplied, performs the most deserving but also the most laborious of functions. The little ones wait trustingly, persuaded that things happen of themselves, while he anxiously resorts to every kind of ingenuity and trouble, wondering whether the right thing will come. Ah, how well long practice has taught me to know the trade, with all its worries and all its joys! Behold me to-day the Providence of a thousand nurselings thrust upon me by my studies. I try a little of everything. The tender leaves of the elm appear to suit. If I serve them up one day, I find them next morning nibbled on the surface, in small patches. Tiny grains of impalpable black dust, scattered here and there, tell me that the intestines have been at work. This gives me a moment of satisfaction which will be readily understood by any breeder of a herd whose diet is unknown. The hope of success gains strength: I know how to feed my vermin. Have I discovered the best method at the first attempt? I dare not think so. I continue therefore to vary the fare, but the results hardly come up to my wishes. The flock refuses my assorted green stuff and even ends by taking a dislike to the elm-leaves. I am beginning to believe that I have failed utterly, when a happy inspiration occurs to me. I have recognized among the bits that go to form the case a few fragments of the mouse-ear hawkweed (Hieracium pilosella). So the Psyche frequents that plant. Why should he not browse it? Let us try. The mouse-ear displays its little round flowers in profusion in a stony field just beside my house, at the foot of the wall where I have so often found Psyche-cases hanging. I gather a handful and distribute it among my different folds. This time the food-problem is solved. The Psyches forthwith settle in solid masses on the hairy leaves and nibble at them greedily in small patches, in which the epidermis of the other surface remains untouched.