BioConcepts

animalculesanimalculi (lat.); Animalcules (ger.)

• 1) Any small animal, including small vertebrates as well as all invertebrates. (OED 2010)
  category protist

  1516

  animalia necessitatis duntaxat gratia perimant, quum venator ab miseri animalculi caede ac laniatu, nihil nisi voluptatem petat.

  More, T. (1516). Utopia (Basiliae 1518): 109.

  1599

  For the Laske […] Boyle the Liver of any animalcle [Germ. Thier], decocte the same, & cause him to eate therof.

  A.M. (1599) (transl.). O. Gaebelkhover, The Boock of Physicke: 131.

  1653

  The assault of Flyes and Gnats, and such like bold Animalcula.

  More, H. (1653). Antidote against Atheisme: 94.

• 2) Any microscopic aquatic organism, including minute animals (such as rotifers) as well as protozoans and other motile single-celled organisms. (OED 2010)
  category protist

  1674

  About two hours distant from this Town there lies an inland lake, called the Berkelse Mere, whose bottom in many places is very marshy, or boggy. Its water is in winter very clear, but at the beginning or in the middle of summer it becomes whitish, and there are then little green clouds floating through it; which, according to the saying of the country folk dwelling thereabout, is caused by the dew, which happens to fall at that time, and which they call honey-dew. This water is abounding in fish, which is very good and savoury. Passing just lately over this lake, at a time when the wind blew pretty hard, and seeing the water as above described, I took up a little of it in a glass phial; and examining this water next day, I found floating therein divers earthy particles, and some green streaks, spirally wound serpent-wise, and orderly arranged, after the manner of the copper or tin worms, which distillers use to cool their liquors as they distil over. The whole circumference of each of these streaks was about the thickness of a hair of one’s head. Other particles had but the beginning of the foresaid streak; but all consisted of very small green globules joined together: and there were very many small green globules as well. Among these there were, besides, very many little animalcules, whereof some were roundish, while others, a bit bigger, consisted of an oval. On these last I saw two little legs near the head, and two little fins at the hindmost end of the body. Others were somewhat longer than an oval, and these were very slow a-moving, and few in number. These animalcules had divers colours, some being whitish and transparent; others with green and very glittering little scales; others again were green in the middle, and before and behind white; others yet were ashen grey. And the motion of most of these animalcules in the water was so swift, and so various, upwards, downwards, and round about, that ’twas wonderful to see: and I judge that some of these little creatures were above a thousand times smaller than the smallest ones I have ever yet seen, upon the rind of cheese, in wheaten flour, mould, and the like.

  van Leeuwenhoek, A. [1674]. [Letter to H. Oldenburg, dated 7 Sept. 1674; Dutch original, transl. by C. Dobell]. In: Dobell, C. (1932/58). Antoni van Leeuwenhoeck and his “Little Animals”: 109-11.
  

  1677

  these animalcula or living Atoms did move […] those very small animalcula did swim gently among one another moving like as Gnats do in the Air

  van Leeuwenhoek, A. (1677). Observations, communicated to the publisher by Mr. Antony van Leewenhoeck, in a Dutch letter of the 9th of Octob. 1676. Here English’d: concerning little animals by him observed in rain-well-sea. and snow water; as also in water wherein pepper had lain infused. Philosophical Transactions 12, 821-831: 82; 8241.

  1982

  animalcule An archaic term for any microscopic organism. 

  Lincoln, R.J., Boxshall, G.A. & Clark, P.F. (1982). A Dictionary of Ecology, Evolution and Systematics: 16.