feathering vs gemmule

feathering

noun
  • Plumage. 

  • The fitting of feathers to arrows. 

  • Visible offshoots of the trails of ink written on overly absorbent paper. 

  • A feathered texture. 

  • An arrangement of small arcs or foils separated by projecting cusps, frequently forming the feather-like ornament on the inner mouldings of arches. 

gemmule

noun
  • Synonym of plumule (“the first bud, or growing point, of a plant embryo, situated above the cotyledons”) 

  • In the obsolete theory of pangenesis propounded by the English scientist Charles Darwin (1809–1882): a hypothetical particle once thought to be the basis of heredity. 

  • Synonym of dendritic spine (“a small membranous protrusion from the dendrite of a neuron that typically receives input from a single axon at the synapse”) 

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