ADVANCED USAGE
     Multiple compressed files can be concatenated. In this case,
     gunzip will extract all members at once. For example:

           gzip -c file1  > foo.gz
           gzip -c file2 >> foo.gz

     Then

           gunzip -c foo

     is equivalent to

           cat file1 file2

     . . . . . . . . . .

     If you wish to create a single archive  file  with  multiple
     members  so  that  members  can  later be extracted indepen-
     dently, use an archiver such as tar or zip. GNU tar supports
     the -z option to invoke gzip transparently. gzip is designed
     as a complement to tar, not as a replacement.