  The paper deals with a class of cooperative functional differential equations
(FDEs) with infinite delay, for which sufficient conditions for persistence and
permanence are established. Here, the persistence refers to all solutions with
initial conditions that are positive, continuous and bounded. The present
method applies to a very broad class of abstract systems of FDEs with infinite
delay, both autonomous and non-autonomous, which include many important models
used in mathematical biology. Moreover, the hypotheses imposed are in general
very easy to check. The results are illustrated with some selected examples.
