The Symbolism of the Fir-Cone

What does the "fir-cone" in the Ninevite sculptures mean? Layard does not explain it. Is it there as the emblem of fecundity, as the pomegranate of Persia and Syria? Has it altogether the same character as the latter fruit? Then—was it carried into Hindostan viâ Cashmir? When? By the first wave of population which broke through the passes of the Parapamisus?