He was seeking them in vain when a volume by Léon Dufour, the famous entomologist, who then lived in the depths of the Landes, fell by chance into his hands, and lit the first spark of that beacon which was presently to decide the definite trend of his ideas. It was this incident which then and there developed the germs already latent within him. These had only awaited such an occasion as that which so fortunately came to pass one evening of the winter of 1854. Fabre offers yet another example of the part so often played by chance in the manifestations of talent. How many have suddenly felt the unexpected awakening of gifts which they did not suspect, as a result of some unusual circumstance! Was it not simply as a result of having read a note by the Russian chemist Mitscherlich on the comparison of the specific characteristics of certain crystals that Pasteur so enthusiastically took up his researches into molecular asymmetry which were the starting-point of so many wonderful discoveries? Again, we need only recall the case of Brother Huber, the celebrated observer of the bee, who, having out of simple curiosity undertaken to verify certain experiments of Réaumur's, was so completely and immediately fascinated by the subject that it became the object of the rest of his life. Again, we may ask what Claude Bernard would have been had he not met Magendie? Similarly Léon Dufour's little work was to Fabre the road to Damascus, the electric impulse which decided his vocation. It dealt with a very singular fact concerning the manners of one of the hymenoptera, a wasp, a Cerceris, in whose nest Dufour had found small coleoptera of the genus Buprestis, which, under all the appearances of death, retained intact for an incredible time their sumptuous costume, gleaming with gold, copper, and emerald, while the tissues remained perfectly fresh. In a word, the victims of Cerceris, far from being desiccated or putrefied, were found in a state of integrity which was altogether paradoxical. Dufour merely believed that the Buprestes were dead, and he gave an attempted explanation of the phenomenon. Fabre, his curiosity and interest aroused, wished to observe the facts for himself; and, to his great surprise, he discovered how incomplete and insufficiently verified were the observations of the man who was at that time known as "the patriarch of entomologists."