pomology vs zoology

pomology

noun
  • A work or treatise written on this subject. 

  • The study of pome fruit and of the cultivation of such fruit. 

  • The study of fruit in general and of the cultivation of fruit. 

zoology

noun
  • A treatise on this science. 

  • The part of biology relating to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct. 

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