  We consider the plane 3 body problem with 2 of the masses small. Periodic
solutions with near collisions of small bodies were named by Poincar\'e second
species periodic solutions. Such solutions shadow chains of collision orbits of
2 uncoupled Kepler problems. Poincar\'e only sketched the proof of the
existence of second species solutions. Rigorous proofs appeared much later and
only for the restricted 3 body problem. We develop a variational approach to
the existence of second species periodic solutions for the nonrestricted 3 body
problem. As an application, we give a rigorous proof of the existence of a
class of second species solutions.
