..there shell be All New dirges. It seems that the last line of last stanza mis-underestimates the 'sap'- part of Homo- (?)

And Spring herself, when she woke at dawn,
Would scarcely know that we were gone.

Alas, how could she have foreseen? Lise Meitner, fission thence /Mendeleev's Periodic Chart superseded with Chart of the Nuclides: the New astrology of all the things you can Do with those. Or be done-by.

(I couldn't emulate her)) Bad meter here, but? ~ 'Catastrophe seen, its villains gone'
We do always slink away, once a spotlight is turned on a lynching.