In the field of zoology his scalpel revealed the complicated structure of the reproductive organs of the Centipedes (Millepedes), hitherto so confused and misunderstood; as also certain peculiarities of the development of these curious creatures, so interesting from the point of view of the zoological philosopher (4/10.), for he had become expert in handling not only the magnifying glass, which was always with him, but also the microscope, which discovers so many infinite wonders in the lowest creatures, yet which was not of particular service in any of the beautiful observations upon which his fame is built. Returning to Avignon, in the possession of his new degree, he commenced an important task which took him nearly twenty years to complete: a painstaking treatise on the Sphaeriaceae of Vaucluse, that singular family of fungi which cover fallen leaves and dead twigs with their blackish fructifications; a remarkable piece of work, full of the most valuable documentation, as were the theses whose subjects I have just detailed; but without belittling the fame of their author, one may say that another, in his place, might have acquitted himself as well. Although he continued to undertake researches of limited interest and importance, although he persisted in dissecting plants, and, although he disliked it, in "disembowelling animals," the fact was that apart from Thursdays and Sundays it was scarcely possible for him to escape from his week's work; hardly possible to snatch sufficient leisure to undertake the studies toward which he felt himself more particularly drawn. Tied down by his duties, which held him bound to a discipline that only left him brief moments, and by the forced hack-work imposed upon him by the necessity of earning his daily bread, he had scarcely any time for observation excepting vacations and holidays. Then he would hasten to Carpentras, happy to hold the key to the meadows, and wander across country and along the sunken lanes, collecting his beautiful insects, breathing the free air, the scent of the vines and olives, and gazing upon Mont Ventoux, close at hand, whose silver summit would now be hidden in the clouds and now would glitter in the rays of the sun. Carpentras was not merely the country in which his wife's parents dwelt: it was, above all, a unique and privileged home for insects; not on account of its flora, but because of the soil, a kind of limestone mingled with sand and clay, a soft marl, in which the burrowing hymenoptera could easily establish their burrows and their nests. Certain of them, indeed, lived only there, or at least it would have been extremely difficult to find them elsewhere; such was the famous Cerceris; such again, was the yellow-winged Sphex, that other wasp which so artistically stabs and paralyses the cricket, "the brown violinist of the clods."