This guest of summer, / The temple-haunting martlet, does approve, / By his loved mansionry, that the heaven's breath / Smells wooingly here: no jutty, frieze, / Buttress, nor coign of vantage, but this bird / hath made his pendant bed and procreant cradle.
Act I, Scene 6 · Banquo
Context
Banquo adds to Duncan's praise of the castle by pointing out that martlets (small birds) have nested all over its walls, which he takes as proof that the air here is pure and healthy.
Analysis
Banquo piles up architectural terms—'jutty, frieze, / Buttress, nor coign of vantage'—in a catalog that mimics the birds covering every surface of the castle. This syntactic accumulation makes the place sound thoroughly inhabited by life and fertility ('procreant cradle'), yet the audience has just heard Lady Macbeth invoke murderous darkness inside these same walls. The gap between Banquo's reading of nature's signs and the reality waiting inside turns his confident observation into a lesson in misreading.
Essay Tip
Support a thesis that Shakespeare uses natural imagery ironically throughout the play—characters who trust nature as a moral guide (like Banquo here) are systematically proven wrong, suggesting that the natural world offers no reliable map to human intention.