If any of your readers could obtain for me some eggs of the Lacerta agilis,¹ I should be greatly obliged. Lizards are most widely distributed, and I want to ascertain whether the eggs will float in sea-water, and, if so, whether they will retain their vitality. A reward of a few shillings (which I would gladly repay as well as postage) offered to schoolboys, would perhaps get these eggs in the proper districts collected. Ch. Darwin, Downe, ² Farnborough, Kent.