tomentum vs tomentum cerebri

tomentum

noun
  • A mass of filamentous hairs on the leaf of a plant. 

  • A network of fine blood vessels between the pia mater and the cerebral cortex. 

  • A covering of fine, soft hairs; a pubescence. 

tomentum cerebri

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