cortex vs vesicle

cortex

noun
  • The tissue of a stem or root that lies inward from the epidermis, but exterior to the vascular tissue. 

  • The outer surface of a piece of flint. 

  • The outer layer of an internal organ or body structure, such as the kidney or the brain. 

vesicle

noun
  • A pocket of embryonic tissue that is the beginning of an organ. 

  • A small sac or cyst or vacuole, especially one containing fluid. A blister formed in or beneath the skin, containing serum. A bleb. 

  • (usually and especially) Such a blister that is less than 5 mm in diameter. 

  • A small cavity formed in volcanic rock by entrapment of a gas bubble during solidification. 

  • A membrane-bound compartment found in a cell. 

  • A small sac filled with juice, one of many constituting the pulp of a fruit such as an orange, lemon, or grapefruit. 

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