Ramanujan's Eisenstein series and powers of Dedekind's eta-function

In this article, we use the theory of elliptic functions to construct theta function identities which are equivalent to Macdonald's identities for A(2), B-2 and G(2). Using these identities, we express, for d = 8, 10 or 14, certain theta functions in the form eta(d)(tau)F(P, Q, R), where eta(tau) is Dedekind's eta-function, and F(P, Q, R) is a polynomial in Ramanujan's Eisenstein series P, Q and R. We also derive identities in the case when d = 26. These lead to a new expression for eta(26)(tau). This work generalizes the results for d = 1 and d = 3 which were given by Ramanujan on page 369 of 'The Lost Notebook'.