Eugène Rey

“ If we apply this to the Cuckoo, we are not astonished if almost every bird lays differently coloured eggs, because the difference of food arising from the various foster-parents, according to their kind and individuality, produces a much larger variety than in other birds. And if we further apply to the Cuckoo the law of heritage, over and above the difference in food, the variation in the eggs would be enormously increased. ”

“ It is clear that apparently similar food can produce different results, for we often see that insects and larvæ, externally alike, have, chemically, quite different bodies; and, again, quite distinct insects are chemically alike. ”

“ This theory supposes that those female Cuckoos whose eggs most resemble those of the nest chosen, have greater chance for the preservation of their offspring than others, whose eggs would be more liable to be destroyed by the foster-parents. ”