  In his `Memoir on Elliptic Divisibility Sequences', Morgan Ward's definition
of the said sequences has the remarkable feature that it does not become at all
clear until deep into the paper that there exist nontrivial such sequences.
Even then, Ward's proof of coherence of his definition relies on displaying a
sequence of values of quotients of Weierstra\ss $\sigma$-functions. We give a
direct proof of coherence and show, rather more generally, that a sequence
defined by a so-called Somos relation of gap 4 always also is given by a three
term Somos relation of all larger gaps 5, 6, 7, $... $.
