milt vs spermatozoa

milt

noun
  • The semen of a male fish. 

  • The spleen, especially of an animal bred for food. 

verb
  • To impregnate (the roe of a fish) with milt. 

spermatozoa

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