gens vs species

gens

noun
  • A host-specific lineage of a brood parasite species.^([W]) 

  • A legally defined unit of Roman society, being a collection of people related through a common ancestor by birth, marriage or adoption, possibly over many generations, and sharing the same nomen gentilicium. 

  • A tribal subgroup whose members are characterized by having the same descent, usually along the male line. 

species

noun
  • A category in the classification of organisms, ranking below genus; a taxon at that rank. 

  • A group of plants or animals having similar appearance. 

  • A mineral with a unique chemical formula whose crystals belong to a unique crystallographic system. 

  • Either of the two elements of the Eucharist after they have been consecrated. 

  • Visible or perceptible presentation; appearance; something perceived. 

  • A component part of compound medicine; a simple. 

  • A particular type of atom, molecule, ion or other particle. 

  • Type or kind. (Compare race.) 

  • Coin, or coined silver, gold, or other metal, used as a circulating medium; specie. 

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