Grocott & Ward, comps. Grocott’s Familiar Quotations, 6th ed. 189-?.
Incubation
Th’ appointed time
With pious toil fulfill’d, the callow young,
Warm’d and expanded into perfect life,
Their little bondage break, and come to light;
A helpless family, demanding food
With constant clamour.
Thomson.—Spring, Line 666.