craw vs trachea

craw

noun
  • The crop of a bird. 

trachea

noun
  • One of the cuticle-lined primary tubes in the respiratory system of an insect, which extend throughout its body. 

  • A thin-walled, cartilaginous tube connecting the larynx to the bronchi. 

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