encephalon vs endbrain

encephalon

noun
  • The area of central nervous system that includes all higher nervous centers, enclosed within the skull and continuous with the spinal cord; the brain. 

endbrain

noun
  • The anterior part of the forebrain; the telencephalon. 

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