cilium vs fibril

cilium

noun
  • Hairs or similar protrusions along the margin of an organ. 

  • One of the fine hairs along an insect's wing. 

  • An eyelash. 

  • A short microscopic hairlike organelle projecting from a eukaryotic cell (such as a unicellular organism or one cell of a multicelled organism) which serve either for propulsion by causing currents in the surrounding fluid or as sensors. 

fibril

noun
  • Any fine, filamentous structure in animals or plants 

  • A fine fibre or filament 

How often have the words cilium and fibril occurred in a corpus of books? (source: Google Ngram Viewer )