VIII 
THE GUANA CO 
175 
the arid plains a few black beetles (Heteromera) might be seen 
slowly crawling about, and occasionally a lizard darted from 
side to side. Of birds we have three carrion hawks, and in the 
valleys a few finches and insect-feeders. An ibis (Theristicus 
melanops—a species said to be found in central Africa) is not 
uncommon on the most desert parts : in their stomachs I found 
grasshoppers, cicadae, small lizards, and even scorpions. 1 At one 
time of the year these birds go in flocks, at another in pairs; their 
cry is very loud and singular, like the neighing of the guanaco. 
The guanaco, or wild llama, is the characteristic quadruped 
of the plains of Patagonia ; it is the South American represent- 
OPUNTIA DARWINII. 
ative of the camel of the East. It is an elegant animal in a 
state of nature, with a long slender neck and fine legs. It is 
very common over the whole of the temperate parts of the con¬ 
tinent, as far south as the islands near Cape Horn. It generally 
lives in small herds of from half a dozen to thirty in each ; but 
on the banks of the St. Cruz we saw one herd which must have 
contained at least five hundred. 
They are generally wild and extremely wary. Mr. Stokes 
was remarkable by the irritability of the stamens, when I inserted either a piece of 
stick or the end of my finger in the flower. The segments of the perianth also 
closed on the pistil, but more slowly than the stamens. Plants of this family, 
generally considered as tropical, occur in North America (Lewis and Clay'ke's Travels , 
p. 221), in the same high latitude as here, namely, in both cases, in 47 0 . 
1 These insects were not uncommon beneath stones. I found one cannibal 
scorpion quietly devouring another. 
