The rotifers or wheel animalcules are fantastic creatures. They were first seen by the Dutchman Antonius van Leeuwenhoek, credited with being the inventor of the microscope. “On the 25th of August,” he wrote to the Royal Society of London with which group of savants patronized by Charles the Second he was in regular correspondence, “I saw in a leaden gutter on the front of the house for a length of five feet some rain water had been standing which had a red color. It occurred to me that this redness might be caused by red animalcules. I took a drop or two of the water and looked at it under the microscope.” He found a confusion of “red-eyed monsters armed with teeth like those of the balance wheel of a watch, which appear to be projecting forward towards the head. They seem to whirl around with a very considerable velocity, by which means a rapid current of water is brought from a distance to the mouth of the creature who thereby is supplied with many invisible food particles.” This discovery is of considerable significance in scientific history because, more than any of his previous findings, it caused the Amsterdam spectacle-maker to question the then widely held belief in the spontaneous generation of living things. “They can,” he wrote the Royal Society in 1774, “continue many months out of water and be dry as dust, in which condition their shape is globular, the bigness exceeds not a grain of sand, and no signs of life appear. Notwithstanding, being put in water, the globule turns itself about, lengthens by slow degrees, becomes in the form of a lively maggot, and most commonly in a few minutes afterwards puts out its wheels and sweeps the water in search of food. But sometimes it may remain a long time in the maggot form and not show its wheels at all.” Such tiny organisms capable of such long periods of suspended animation, Leeuwenhoek held, could be blown by the wind for long distances. Thus the sudden appearance of living animals in supposedly lifeless water did not indicate they had been born or created there. The microscope designer had found, moreover, an hitherto unknown race, giants of the microscopic world and among the most fantastic of all animals—the rotifers.