In a largely heuristic but fascinating recent paper, Hu and Meyer have given a "formula" for the Feynman integral of a random variable f f on Wiener space in terms of the expansion of f f in Wiener chaos. The surprising properties of scaling in Wiener space make the problem of rigorously connecting this formula with the usual definition of the analytic Feynman integral a subtle one. One of the main tools in carrying this out is our definition of the ’natural extension’ of p p th homogeneous chaos in terms of the ’scale-invariant lifting’ of p p -forms on the white noise space L 2 ( R + ) {L^2}({\mathbb {R}_ + }) connected with Wiener space. The key result in our development says that if f p {f_p} is a symmetric function in L 2 ( R + p ) {L^2}(\mathbb {R}_ + ^p) and ψ p ( f p ) {\psi _p}({f_p}) is the associated p p -form on L 2 ( R + ) {L^2}({\mathbb {R}_ + }) , then ψ p ( f p ) {\psi _p}({f_p}) has a scaled L 2 {L^2} -lifting if and only if the ’ k k th limiting trace’ of f p {f_p} exists for k = 0 , 1 , … , [ p / 2 ] k = 0,1, \ldots ,[p/2] . This necessary and sufficient condition for the lifting of a p p -form on white noise space to a random variable on Wiener space is a worthwhile contribution to white noise theory apart from any connection with the Feynman integral since p p -forms play a role in white noise calculus analogous to the role played by p p th homogeneous chaos in Wiener calculus. Various k k -traces arise naturally in this subject; we study some of their properties and relationships. The limiting k k -trace plays the most essential role for us.