In this paper we discuss a generalization of Fueter's theorem which states
that whenever f(x(o),(x) under bar) is holomorphic in x(o) + (x) under bar,
then it satisfies D square f = 0, D = partial derivative (xo) + i partial
derivative (x1) + j partial derivative (x2) + k partial derivative (x3) bei
ng the Fueter operator.