An`i*mal"cule (#), n. [As if fr. a L. animalculum, dim. of animal.]
1.
A small animal, as a fly, spider, etc.
[Obs.]
Ray.
2. Zool.
An animal, invisible, or nearly so, to the naked eye. See Infusoria.
⇒ Many of the so-called animalcules have been shown to be plants, having locomotive powers something like those of animals. Among these are Volvox, the Desmidiacae, and the siliceous Diatomaceae.
Spermatic animalcules. See Spermatozoa.
© Webster 1913.