  For $\Cal A\subset L^1_{loc}(\Bbb J,X)$ let $\Cal M\Cal A$ consist of all
$f\in L^1_{loc}$ with $ M_h f (\cdot):=\frac {1}{h}\int_{0}^{h}f(\cdot +s)\,ds
\in \Cal A$ for all $h>0$. Here $X$ is a Banach space, $\Bbb J= (\alpha
,\infty), [\alpha ,\infty)$ or $\Bbb R$. Usually $\Cal A\subset\Cal M\Cal
A\subset \Cal M^2\Cal A\subset ...$.
  The map $ \Cal A \to \Cal {D}'_{\Cal A}$ is iteration complete, that is $
\Cal {D}'_{\Cal {D}'_{\Cal A}}= \Cal {D}'_{\Cal A}$. Under suitable assumptions
$\widetilde {\Cal M}^n \Cal {A}= \Cal A + \{T^{(n)} : T \in \Cal A\}$, and
similarly for $\Cal {M}^n \Cal A$. Almost periodic $X$-valued distributions
$\h'_{\A}$ with $\A = $ almost periodic (ap) functions are characterized in
several ways.
  Various generalizations of the Bohl-Bohr-Kadets theorem on the almost
periodicity of the indefinite integral of an ap or almost automorphic function
are obtained.
  On $ \Cal {D}'_{\Cal E} $, $ \Cal E $ the class of ergodic functions, a mean
can be constructed which gives Fourier series. Special cases of $\Cal A $ are
the Bohr ap, Stepanoff ap, almost automorphic, asymptotically ap, Eberlein
weakly ap, pseudo ap and (totally) ergodic functions $(\T)\E$.
  Then always $\Cal {M}^n \Cal A$ is strictly contained in $ \Cal {M}^{n+1}
\Cal A$. The relations between $\m^n \E$, $\m^n\T\E$ and subclasses are
discussed. For many of the above results a new $(\Delta)$-condition is needed,
we show that it holds for most of the $\A$ needed in applications.
  Also, we obtain new tauberian theorems for $f\in L^1_{loc}(\Bbb J,X)$ to
belong to a class $\A$ which are decisive in describing the asymptotic behavior
of unbounded solutions of many abstract differential-integral equations. This
generalizes various recent results
