If the ``glue'' which binds quarks within hadrons takes the form of strings,
then a virial theorem may be derived which shows how the total hadron four
momentum splits up into a quark contribution plus a glue contribution. The
hadrons made up of light quarks exhibit an equipartion of four momentum into
equal parts quarks and glue. The agreement with the experimental ``parton''
distribution four momentum sum rule is quite satisfactory as is the string
fragmentation model.Comment: four pages, RevTeX format, one figure *.ep