The Natural History of Animalcules

Full Title

The Natural History of Animalcules:Containing descriptions of all the known species of infusoria with instructions of procuring and viewing them, etc.

This review of what was known at the time mentioned Leeuwenhoek only once, on p. 70, when writing about Vibrio undula, (Spirillus undula, E. The wavy Vibrio:

Leeuwenhoek, whose measurements are generally vague, informs us that its diameter is much less than the tail of the human spermatic animalcule, and adds this remark: “That as this minute creature, of whose animated existence there can be no doubt, can inflect its extremities at pleasure, we must conclude that tendons and muscles are essential to its existence as in larger animals; if to these we add alimentary organs, and those of sensation, the mind is lost in the astonishment which arises from the impression of infinite in the indefinitely small.”