"We can now easily conceive," he says, "that in all rain-water which is collected from gutters in cisterns, and in all waters exposed to the air, animalcules may be found; for they may be carried thither by the particles of dust blown about by the winds."
Most remarkable is its resemblance to the adult form of the Wheel animalcules, or Rotifera, which retain the prae-oral ciliated band as their chief organ of locomotion and prehension throughout life.
Needham (1713-1781) that animalcules did not develop in vegetable infusions which had been boiled and were kept in properly closed vessels.
How would you define animalcules? Add your definition here.