Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Of all animals, birds have perhaps afforded me the most pleasure; but most of the fresh knowledge I have been able to collect in this department is contained in a larger work (Argentine Ornithology), written in collaboration with Dr P. L. Sclater is part author. As I have not gone over any of the subjects dealt with in that work, bird-life has not received more than a fair share of attention in the present volume.