"Close at our own gate is a pretty neem tree, the '_Melia azadirachta_,' a species now naturalized in Provence and other parts of the south of France. High up in a fork a small nest was visible, and projecting over it on one side a black forked tail that could belong to nothing but the King-Crow. Of this bird we have already taken during the last six weeks at least fifty nests, and in many cases where we had left the empty nest in _statu quo_, we found it a week later with a fresh batch of eggs laid therein. Many birds will never return to a nest which has once been robbed, but others, like the King-Crow and the Little Shrike (_Lanius vittatus_) will continue laying even after the nest has been _twice_ robbed. The very day after the nest has been cleared of perhaps four slightly incubated eggs, a fresh one that otherwise would assuredly never have seen the light is laid, and that, too, a fertile egg, which, if not meddled with, will be hatched off in due course. It might be supposed that immediately on discovering their loss, nature urged the birds to new intercourse, the result of which was the fertile egg, and this, in some cases, is probably really the case; Martins and others of the Swallow kind being often to be seen busy with 'love's pleasing labour' before their eggs have been well stowed away by the collector. But this will not account for instances that I have observed of birds in confinement, who separated from the male before they had laid their full number, and then later, just when they began to sit deprived of their eggs, straightway laid a second set, neither so large nor so well coloured as the first, but still fertile eggs that were duly hatched. But for the removal of the first set, these subsequent eggs would never have been developed or laid. Now, the theory has always been that the contact of the sperm- and germ-cells causes the development and fertilization of the latter. In these cases no fresh accession of sperm-cells was possible, and hence it would seem as if in some birds the female organs were able to store up living sperm-cells, which only work to fertilize and develop ova in the event of some accident rendering it necessary, and which otherwise ultimately lose vitality and pass away without action.