 The isotropy algebra of such a generic point, the Lie algebra of "G" and the Lie algebra of "H" give the complexifications of the first three rows of the Freudenthal magic square.Other Hermitian symmetric spaces yields prehomogeneous vector spaces whose generic points define Jordan algebras in a similar way.The Jordan algebra "J"("m"−1) in the last row is the spin factor (which is the vector space R"m"−1 ⊕ R, with a Jordan algebra structure defined using the inner product on R"m"−1).