The nineteenth century saw numerous transfers and attempted transfers of animal populations, mostly as the result of the spread of European agriculture. The exchange of animal populations facilitated by the acclimatization societies that were established in Europe, North America, Australia, among other places, had more complicated meanings. Introduced aliens were often appreciated or deplored in the same terms that were applied to human migrants. Some animal acclimatizations were part of ambitious attempts to transform entire landscapes. Such transfers also broached or blurred the distinction between the domesticated and the wild. The intentional enhancement of the fauna of a region is a forceful assertion of human power. But most planned acclimatizations failed if they moved beyond the drawing board. And those that succeeded also tended to undermine complacent assumptions about human control.