For the sacredness of the head especially, see the Golden Bough, i. 187-193.
The myth, as given by Plutarch, is to be found also in Livy, i. 9; Serv. ad Æn., vi. 55; and in Varro, quoted by Festus, p. 351. The word occurs in Martial, i. 35. 6 and 7; iii. 93. 25; xii. 42. 4, 95. 5 (Friedländer says nothing), and Catullus, lxi. 134 (Robinson Ellis has nothing to say).
Hartley, Science of Fairy Tales, pp. 279-281, for examples. The tale of Servius is also told by Ovid, F., vi. 577.
It is interesting to note that two hundred years ago Boxhorn, in commenting on this passage of Plutarch, laid down a fundamental proposition of the science of folk-lore:—"Mortales cum inquirerent in caussas rerum, nec invenirent, pro libitu suo verisimiles sunt commenti. Sic ut fabulæ proponerentur tanquam caussæ rerum, cum res ipsæ essent causeæ fabularum." See his edition of the Roman Questions, printed in vol. v. of the Thesaurus of Grævius (Lugd., Batavor, 1696).
Ethnology in Folk-Lore, pp. 120 ff. Mr. Gomme, however, argues that the fear of dead kindred was borrowed by the Aryans from the non-Aryan inhabitants of Europe. But why may not the pro-ethnic Aryans, as well as other savages, have had, at one stage of their development, a fear of dead kindred?