The little things are infinitely the most important. ~ Irish-Scottish physician and writer Arthur Conan Doyle
Dutch tradesman and amateur scientist Antonie van Leeuwenhoek (1632–1723) handcrafted microscopes as a hobby, raising the power of their magnification to a new level. This afforded him a vista of the miniature as never before. His curiosity had him peering at all sorts of organic samples; leading to his discovery of a diverse variety of microorganisms; what Leeuwenhoek termed animalcules, which made “pleasing and nimble” movements.
Among all the marvels that I have discovered in Nature, these little animals are the most marvelous of all. ~ Antonie van Leeuwenhoek
Leeuwenhoek wrote no books but starting in 1673 he began writing letters to the newly formed Royal Society of London, describing what he had seen with his microscopes. His first letter relayed his observations of bee stings. He kept writing for 50 years.
A microbe is an organism too tiny to be seen without a microscope: a microorganism. Microbes comprise a diverse variety of unicellular organisms, including virus, bacteria, archaea, fungi, protists, microscope plants (green algae), and animals such as plankton, planarian, and mites. While most microbes are prokaryotes, many are eukaryotes, including amoeba, which are generally considered unicellular.
The essential simplicity of microbes is largely an illusion. ~ English biologist Brian Ford