After this, nearly two thousand years passed with no progress in natural history; even for two centuries after the revival of learning, we find nothing worthy of note. Swammerdam, a Dutch entomologist, in the middle of the 17th century, wrote a general history of insects, also, "The Natural History of Bees." He and his English cotemporary, Ray, showed their ability as naturalists by founding their systems on the insect transformations. They also revived the study and practice of anatomy, which had slept since its first introduction by Aristotle, as the great stepping-stone in zoological progress. Ray also gave special attention to Hymenoptera, and was much aided by Willoughby and Lister. At this time Harvey, so justly noted for his discovery of the circulation of the blood, announced his celebrated dictum, "Omnia ex ovo,"--all life from eggs--which was completely established by the noted Italians, Redi and Malpighi. Toward the middle of the 18th century, the great Linnæus--"the brilliant Star of the North"--published his "System Naturæ," and threw a flood of light on the whole subject of natural history. His division of insects was founded upon presence, or absence, and characteristics, of wings. This, like Swammerdam's basis, was too narrow, yet his conclusions were remarkably correct. Linnæus is noted for his accurate descriptions, and especially for his gift of the binomial method of naming plants and animals, giving in the name the genus and species, as, Apis mellifica. He was also the first to introduce classes and orders, as we now understand them. When we consider the amount and character of the work of the great Swede we can but place him among the first, if not as the first, of naturalists. Cotemporary with Linnæus (also written Linné) was Geoffroy, who did valuable work in defining new genera. In the last half of the century appeared the great work of a master in entomology, DeGeer, who based his arrangement of insects on the character of wings and jaws, and thus discovered another of nature's keys to aid him in unlocking her mysteries. Kirby well says: "He united in himself the highest merit of almost every department of entomology." As a scientist, an anatomist, a physiologist, and as the observant historian of the habits and economy of insects, he is above all praise. What a spring of self-improvement, enjoyment and of public usefulness, is such an ability to observe, as was possessed by the great DeGeer.