craw vs pharynx

craw

noun
  • The crop of a bird. 

pharynx

noun
  • The part of the alimentary canal and respiratory tract that extends from the back of the mouth and nasal cavity to the larynx and esophagus. 

  • The part of the alimentary canal immediately behind the mouth in invertebrates that may be thickened and muscular, eversible and toothed, or adapted as a suctorial organ. 

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