Very good background – unable to find an original

https://books.google.co.nz/books?id=WXIJHKnfIJAC&pg=PA208&lpg=PA208&dq=gallbladder+is+prehistoric+no+longer+needed&source=bl&ots=8mubgKqJoQ&sig=rxFnndQFtYlbMhwXYxBkKZrI4aA&hl=en&sa=X&ei=h1NEVYnhNeS3mAWp5oCoAg&ved=0CFQQ6AEwCQ#v=onepage&q=gallbladder%20is%20prehistoric%20no%20longer%20needed&f=false