A path bundle is a set of 2a paths in an n-cube, denoted Qn, such that every path has the same length, the paths partition the vertices of Qn, the endpoints of the paths form two subcubes of Qn, and the endpoints of each path are complements. This paper shows that a path bundle exists if and only if n > 0 is odd and 0 a n - log2 (n + 1) .