If I do this:

#+BEGIN_SRC emacs-lisp

(setq animals '(gazelle giraffe lion tiger))

#+END_SRC

#+RESULTS:

and then this

#+begin_src emacs-lisp

(defun print-elements-of-list (list)

"Print each element of LIST on a line of its own."

(while list

(print (car list))

(setq list (cdr list))))

#+end_src

#+RESULTS:

: print-elements-of-list

and finally

#+BEGIN_SRC emacs-lisp

(print-elements-of-list animals)

#+END_SRC

I get nothing for results and "Code block produced no output." in Messages. Why can't it print out? Same code works fine in the IELM buffer.