Five eggs, pen-scribbled o’er with ink their
shells,
Resembling writing scrawls which fancy
reads,
As nature’s poesy and pastoral spells.
‘The Yellowhammer’s Nest’ by John Clare
ARE not bird’s eggs perfect things? Inside the cover of eggshell, which is a cold mineral, the embryo of a warm-blooded bird grows in a supportive substance, yolk, until