'git commit' ignoring args?

With the latest git as of this writing, executing

	git commit Makefile stylesheet.xsl

results in an attempt to commit the above files, and also another file 
book.xml.  book.xml is modified, but I do not wish to check it in at 
this time, so I did not list it as an argument to 'git commit'.

The only commit in the repository is the initial commit.

#
# Updated but not checked in:
#   (will commit)
#
#       modified: Makefile
#       modified: book.xml
#       new file: stylesheet.xsl
#
#
# Untracked files:
#   (use "git add" to add to commit)
#
#       book.pdf

Expected behavior is that Makefile and stylesheet.xsl would be checked 
in, but not book.xml.

	Jeff