A class E of entire functions of
zero order and with widely spaced zeros has been defined and it is proved that if
f ∈ E then f′,f′′,⋯∈ E. Furthermore f is of index one. This class includes many
functions which are both of bounded index and arbitrarily slow growth. If f is any
transcendental entire function then there is an entire function g of unbounded index
with the same asymptotic behavior. When f is of infinite order then it is of
unbounded index and we simply take g = f. When f is of finite order we give the
construction for g.