Thanks. That worked.
It turns out, the newly-created WordPress installation for 3.8.1 didn’t have a .htaccess file. So I had to copy over the .htaccess from my old WordPress installation. Which begs the question: Why didn’t my new installation have a .htaccess file? Shouldn’t it be created as part of the WordPress installation procedure?
In fact, none of the permalinks work. I cannot navigate to any page from the base WordPress URL. I cannot “Read More…” from any post. I cannot go to the “Next” page of post listings. I cannot go to any “Archives” month/year. I cannot go to any of the “Pages” that were defined for this blog.