What's the difference between animalcule and animalculism?

Animalcule

Definition:

• (n.) An animal, invisible, or nearly so, to the naked eye. See Infusoria.
• (n.) A small animal, as a fly, spider, etc.

Example Sentences:

• (1) It is particularly appropriate for an assemblage of protozoologists to pay homage to this intrepid "philosopher in little things," a man with an insatiable curiosity about his wee animalcules, on the tricentenary of his discovery of them, since it was an event of such long-lasting significance.

Animalculism

Definition:

• (n.) The theory which seeks to explain certain physiological and pathological phenomena by means of animalcules.

Example Sentences:

• (1) It is particularly appropriate for an assemblage of protozoologists to pay homage to this intrepid "philosopher in little things," a man with an insatiable curiosity about his wee animalcules, on the tricentenary of his discovery of them, since it was an event of such long-lasting significance.