I now collect passages on the expurgators from Mr. Murray's writings.
EXPURGATION
"The middle and later generations of the Homeric poets ... were mainly responsible for the work of expurgation."
"Homer has cut out" certain stories of human sacrifice, cannibalism, and "mutilations of the Hesiodic gods" "for their revoltingness" (p. 122).
"Homer, if we may use that name to denote the authors of the prevailing tone of the Iliad" (p. 131).
So far the "expurgations" appear to have been done mainly by the Homeric poets themselves "in the middle and later generations." Yet, as to superstitions, the first uncontaminated Achaean poets must have been the purest of all.
It is admitted that the poets did not in the same way "expurgate" the "Cyclic" epics.
"If the educational use of the Iliad began in Ionia as early as the eighth century, which is likely enough, we can hardly help supposing that it had some share in these processes of purification with which we have been dealing" (p. 133).
Here it appears that, probably by the eighth century, the Iliad was a distinct poem, recognised as such, and subject to processes of purification from which the Cypria, for example, and other "Cyclic" poems escaped.