Histology is the scientific study of the tiniest cells that make up plants and animals. If you're interested in histology, you need to get a microscope.
Some biologists are most fascinated with the microscopic — so small they're invisible without a microscope — details of organisms. These scientists study histology, examining the cells of plant and animal tissues. While the Greek root of the word histology is histo, or "anything that stands upright," it is used in medical terminology to talk about tissues. The Greek suffix ology simply means "branch of science."