achene vs utricle

achene

noun
  • A small, dry, indehiscent fruit, containing a single seed, as in the buttercup. 

utricle

noun
  • A dry indehiscent one-seeded fruit with thin membranous pericarp, similar to an achene and found in the beet and dock plants. 

  • The larger of the two fluid-filled cavities forming part of the membranous labyrinth in the vertebrate inner ear (the other being the saccule) and into which the semicircular canals open. It contains hair cells and otoliths which send signals to the brain concerning the orientation of the head. 

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