It was pointed out in Where I can find the CD version of Stan Wagon - "Mathematica in action" 3rd ed. book? that the code for Wagon's book is available at http://extras.springer.com/2010/978-0-387-75366-9
I have downloaded all the notebooks from that site, but when I click on any of them, it will open up in Mathematica, but all I see is the section headings. For example when I open the notebook for chapter 1 I get the following
I am using Mathematica 22.214.171.124 on mac os x. Is there some trick that I need to employ to actually see the code?