lymph system vs lymphatic system

lymph system

lymphatic system

noun
  • In mammals, including humans, a network of lymph vessels and lymph nodes that transport fluid, fats, proteins, and lymphocytes to the bloodstream as lymph, and remove microorganisms and other debris from tissues. 

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