The Desert Pampas. 19 
dragged like an idle rope behind it! Yet, if one is 
brought to a tree, it will take to it as readily as a 
duck to water, or an armadillo to earth, climbing 
up the trunk and about the branches with a monkey- 
hike agility. How reluctant Nature seems in some 
cases to undo her own work! How long she will 
allow a specialized organ, with the correlated 
instinct, to rest without use, yet ready to flash forth 
on the instant, bright and keen-edged, as in the 
ancient days of strife, ages past, before peace came 
to dwell on earth ! 
The avi-fauna is relatively much richer than the 
mammalia, owing to the large number of aquatic 
species, most of which are migratory with their 
“‘ breeding” or “ subsistence-areas ” on the pampas. 
In more senses than one they constitute a “ floating 
population,” and their habits have in no way been 
modified by the conditions of the country. The 
order, including storks, ibises, herons, spoonbills, 
and flamingoes, counts about eighteen species; and 
the most noteworthy birds init are two great ibises 
nearly as large as turkeys, with mighty resonant 
voices. The duck order is very rich, numbering at 
least twenty species, including two beautiful upland 
geese, winter visitors from Magellanic lands, and 
two swans, the lovely black-necked, and the pure 
white with rosy bill. Of rails, or ralline birds, 
there are ten or twelve, ranging from a small 
spotted creature no bigger than a thrush to some 
large majestic birds. One is the courlan, called 
“crazy widow” from its mourning plumage and 
long melancholy screams, which on still evenings 
may be heard a league away. Another is the 
