infusorium

Further, we find in those subterraneous waters a species of the sun infusorium (_Actinophrys_), which is especially frequent in the mines of Klausthal.

Scientific American Supplement, No. 664, September 22,1888 Various

Up to that time the chief aim in the classification of the animal kingdom was to arrange all the animals from lowest to highest, from the infusorium to man, in one long and continuous series.

The Evolution of Man — Volume 1 Ernst Heinrich Philipp August Haeckel 1876

Every animal that has only one cell-nucleus, every amoeba, every gregarina, every infusorium, is unicellular, and remains unicellular whatever variety of matter it feeds on.

The Evolution of Man — Volume 1 Ernst Heinrich Philipp August Haeckel 1876

Ehrenberg calculated that a single infusorium might make a cube of rock!

More Letters of Charles Darwin — Volume 1 Charles Darwin 1845

"conduct in general," the conduct of an "infusorium or a cephalopod," or even of wind-mills or water-wheels, it is not surprising if the authority of the moral law seems to be undermined, and that "devout souls" are apprehensive of the results of science.

Browning as a Philosophical and Religious Teacher Henry Jones 1887

The most numerous of the compounds of the human aggregate are known to physiology as microbes, bacteria, and bacilli; but amongst them our microscopes discover only comparative monsters, "those that are to the ordinary infinitesimal organisms as the elephant is to the invisible infusorium." [

Reincarnation A Study in Human Evolution Th. Pascal