Mr.
Hudson is a strong disbeliever in evolution, but he appears to have been so much struck by the imperfect instincts of the Molothrus bonariensis that he quotes my words, and asks, "Must we consider these habits, not as especially endowed or created instincts, but as small consequences of one general law, namely, transition?" Various birds, as has already been remarked, occasionally lay their eggs in the nests of other birds.
This habit is not very uncommon with the Gallinaceae, and throws some light on the singular instinct of the ostrich.
In this family several hen birds unite and lay first a few eggs in one nest and then in another; and these are hatched by the males.