INTRODUCTION xi 
instance the Neotropical or South American char- 
acter), existing side by side with the unmodified 
forms: a Thrush, a Siskin, a Swallow, an Owl, a 
Duck, a Dove, a Plover, etc., hardly (and some- 
times not at all) distinguishable specifically from 
Old World forms. And along with those modified 
and unmodified forms—Asiatic, European and North 
American—the distinctly Neotropical forms. Among 
these last there are species that have a profound 
interest to the student of the evolution of the bird life 
of the globe. They are survivals of an incalculably 
remote period in the earth’s history when the greater 
part of the Southern Hemisphere was land; when 
South America, South Africa and Australasia were 
parts of one continent. Among these forms, which 
have struthious and even older affinities, are the 
Rheas, the Crypturi (the Partridges of South America) 
and the Crested Screamer, which Huxley supposed 
to be related by descent to the Archzopteryx. 
To go back to the statement made at the beginning 
of this Introduction—that the one interest of this 
book is in the account of the birds’ habits—I am 
tempted in conclusion to add a purely personal 
note—a memory of an incident of thirty years ago. 
About the time of the publication of Argentine 
Ornithology (1889) a small book of a different kind 
by me was issued—a fictitious record of romantic 
adventures, entitled The Purple Land. It happened 
that a copy was sent to an elder brother of mine, 
living in the city of Cordova, in the Western Argen- 
tine province of that name. It was sent by another 
