Published online by Cambridge University Press: 20 November 2018
It is well-known that odd dimensional spheres carry a normal contact structure [6], Blair, Ludden and Yano [2] have recently studied a more general structure whose non-trivial example is an even dimensional sphere. Recently, the present author introduced the notion of almost contingent structures [8] with a view to develop a unified theory of various existing structures on a differentiable manifold. It is the purpose of this paper to show that even as well as odd dimensional spheres carry an almost contingent structure. In the sequel, each manifold introduced is C∞, arcwise connected and satisfies the second axiom of countability.