etended to be a virgin. The Druids announced that the remedy was to
slay the son of an undefiled couple and sprinkle the doorposts and the
land with his blood. Such a youth was found, but at his mother's request
a two-bellied cow, in which two birds were found, was offered in his
stead.[814] In another instance in the _Dindsenchas_, hostages,
including the son of a captive prince, are offered to remove plagues--an
equivalent to the custom of the Gauls.[815]

Human sacrifices were also offered when the foundation of a new building
was laid. Such sacrifices are universal, and are offered to propitiate
the Earth spirits or to provide a ghostly guardian for the building. A
Celtic legend attaches such a sacrifice to the founding of the monastery
at Iona. S. Oran agrees to adopt S. Columba's advice "to go under the
clay of this island to hallow it," and as a reward he goes straight to
heaven.[816] The legend is a semi-Christian form of the memory of an old
pagan custom, and it is attached to Oran probably because he was the
first to be buried in the island. In another version, nothing is said of
the sacrifice. The two saints are disputing about the other world, and
Oran agrees to go for three days into the grave to settle the point at
issue. At the end of that time the grave is opened, and the triumphant
Oran announces that heaven and hell are not such as they are alleged to
be. Shocked at his latitudinarian sentiments, Columba ordered earth to
be piled over him, lest he cause a scandal to the faith, and Oran was
accordingly buried alive.[817] In a Welsh instance, Vortigern's castle
cannot be built, for the stones disappear as soon as they are laid. Wise
men, probably Druids, order the sacrifice of a child born without a
father, and the sprinkling of the site with his blood.[818] "Groaning
hostages" were placed under a fort in Ireland, and the foundation of the
palace of Emain Macha was also laid with a human victim.[819] Many
similar legends are connected with buildings all over the Celtic area,
and prove the popularity of the pagan custom. The sacrifice of human
victims on the funeral pile will be discussed in a later chapter.

Of all these varieties of human sacrifice, those offered for fertility,
probably at Beltane or Midsummer, were the most important. Their
propitiatory nature is of later origin, and their real intention was to
strengthen the divinity by whom the processes of growth were directed.
Still earlier, one vi