flora vs zoology

flora

noun
  • Plants considered as a group, especially those of a particular country, region, time, etc. 

  • The microorganisms that inhabit some part of the body. 

  • A book describing the plants of a country, region, time, etc. 

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 flora and zoology occurred in a corpus of books? (source: Google Ngram Viewer )