Summary

Thanks MN for essay ["Die Congerien", Abh. Geol. Bundesanst. Wien 7 (1875)]. It is the best case CD has met, showing "direct influence of conditions of life on the organization". A. Hyatt has come to same conclusion: that closely similar forms may be derived from distinct lines of descent. CD did not emphasise in Origin the direct action of environment on modification of species; most of the best evidence has been observed since its publication.