Pasteur’s tour through the Avignon region had sericiculture for its object. For some years, the Silk-worm-nurseries had been in confusion, ravaged by unknown plagues. The worms, for no appreciable reason, were falling into a putrid deliquescence, and then hardening, so to speak, into plaster sugar-plums. The downcast peasant saw one of his chief crops disappearing; after great trouble and expense, he had to fling his nurseries on the dust-heap. A few words were exchanged on the prevailing blight; and then, without further preamble, my visitor said: “I should like to see some cocoons. I have never seen any; I know them only by name. Could you get me some?” “Nothing easier. My landlord happens to sell cocoons; and he lives in the next house. If you will wait a moment, I will bring you what you want.” Four steps took me to my neighbour’s, where I crammed my pockets with cocoons. I came back and handed them to the savant. He took one; he turned and turned it between his fingers; he examined it curiously, as one would a strange object from the other end of the world. He put it to his ear and shook it. “Why, it makes a noise!” he said, quite surprised. “There’s something inside!” “Of course there is.” “What is it?” “The chrysalis.” “How do you mean, the chrysalis?” “I mean the sort of mummy into which the caterpillar changes before becoming a Moth.” “And has every cocoon one of those things inside it?” “Obviously. It is to protect the chrysalis that the caterpillar spins.” “Really!” And without more words, the cocoons passed into the pocket of the savant, who was to instruct himself at his leisure touching that great novelty, the chrysalis. I was struck by this magnificent assurance. Pasteur had come to regenerate the Silkworm, while knowing nothing about caterpillars, cocoons, chrysalids or metamorphoses. The ancient gymnasts came naked to the fight. The talented combatant of the plague of our Silk-worm-nurseries hastened to the battle likewise naked, that is to say, destitute of the simplest notions about the insect which he was to deliver from danger. I was staggered; nay, more, I was thunderstruck. I was not so much amazed by what followed. Pasteur was occupied at the time with another question, that of the improvement of wine by heating. Suddenly changing the conversation, “Show me your cellar,” he said. I! I show my cellar, my private cellar, poor I, lately, with my pitiful teacher’s salary, could not allow myself the luxury of a little wine and used to make a sort of small cider by setting a handful of brown sugar and some grated apples to ferment in a jar! My cellar! Show my cellar! Why not my barrels, my cobwebbed bottles, each labelled with its year and quality! My cellar! Full of confusion, I evaded the request and tried to change the subject. But he persisted: “Show me your cellar, please.”