Various, Encyclopaedia Britannica, 11th Edition…
“ CYTOLOGY (from κύτος, a hollow vessel, and λόγος, science) , the scientific study of the “cells” or living units of protoplasm (q.v.) , of which plants and animals are composed. All the higher, and the great majority of the lower, plants and animals are composed of a vast number of these vital units or “cells.” In the case of many microscopic forms, however, the entire organism, plant or animal, consists throughout life of a single cell. Familiar examples of these “unicellular” forms are Bacteria and Diatoms among the plants, and Foraminifera and Infusoria among the animals. ”
