My cocoons were all hatched, and the problem was still obscure. Should I begin all over again in the fourth year? I did not do so, for the reason that it is difficult to observe a nocturnal butterfly if one wishes to follow it in all its intimate actions. The lover needs no light to attain his ends; but my imperfect human vision cannot penetrate the darkness. I should require a candle at least, and a candle would be constantly extinguished by the revolving swarm. A lantern would obviate these eclipses, but its doubtful light, interspersed with heavy shadows, by no means commends it to the scruples of an observer, who must see, and see well.
Moreover, the light of a lamp diverts the butterflies from their object, distracts them from their affairs, and seriously compromises the success of the observer. The moment they enter, they rush frantically at the flame, singe their down, and thereupon, terrified by the heat, are of no profit to the observer. If, instead of being roasted, they are held at a distance by an envelope of glass, they press as closely as they can to the flame, and remain motionless, hypnotised.
THE GREAT PEACOCK MOTH. THE PILGRIMS
DIVERTED BY THE LIGHT OF A LAMP.
One night, the female being in the dining-room, on the table, facing the open window, a petroleum lamp, furnished with a large reflector in opaline glass, was hanging from the ceiling. The arrivals alighted on the dome of the wire-gauze cover, crowding eagerly about the prisoner; others, saluting her in passing, flew to the lamp, circled round it a few times, and then, fascinated by the luminous splendour radiating from the opal cone of light, clung there motionless under the reflector. Already the children were raising their hands to seize them. "Leave them," I said, "leave them. Let us be hospitable: do not disturb the pilgrims who have come to the tabernacle of the light."
During the whole evening not one of them moved. Next day they were still there. The intoxication of the light had made them forget the intoxication of love.
With creatures so madly in love with the light precise and prolonged experimentation is impracticable the moment the observer requires artificial light. I renounced the Great Peacock and its nocturnal habits. I required a butterfly with different habits; equally notable as a lover, but seeking out the beloved by day.
Before going on to speak of my experiments with a subject fulfilling these conditions, let me break the chronological order of my record in order to say a few words concerning another insect, which appeared after I had completed these inquiries. I refer to the Lesser Peacock (Attacus pavonia minor, Lin.).
Some one brought me, from what locality I do not know, a superb cocoon enveloped in an ample wrapping of white silk. From this covering, which lay in large irregular folds, the chrysalis was easily detached; in shape like that of the Great Peacock, but considerably less in size. The anterior extremity, which is defended by an arrangement of fine twigs, converging, and free at the converging ends, forming a device not unlike an eel-pot, which presents access to the chrysalis while allowing the butterfly to emerge without breaking the defence, indicated a relative of the great nocturnal butterfly; the silk-work denoted a spinning caterpillar.