102 
BAHIA BLANCA 
CHAP. 
carried it to a pool of water ; not only was the little animal 
unable to swim, but I think without help it would soon have 
been drowned. 
Of lizards there were many kinds, but only one (Proctotretus 
multimaculatus) remarkable from its habits. It lives on the 
bare sand near the sea-coast, and from its mottled colour, the 
brownish scales being speckled with white, yellowish red, and 
dirty blue, can hardly be distinguished from the surrounding 
surface. When frightened, it attempts to avoid discovery by 
feigning death, with outstretched legs, depressed body, and 
closed eyes : if further molested, it buries itself with great 
quickness in the loose sand. This lizard, from its flattened 
body and short legs, cannot run quickly. 
I will here add a few remarks on the hybernation of animals 
in this part of South America. When we first arrived at Bahia 
Blanca, September 7th, 1832, we thought nature had granted 
scarcely a living creature to this sandy and dry country. By 
digging, however, in the ground, several insects, large spiders, 
and lizards were found in a half torpid state. On the 1 5 th a 
few animals began to appear, and by the 18th (three days 
from the equinox) everything announced the commencement 
of spring. The plains were ornamented by the flowers of a 
pink wood-sorrel, wild peas, oenotherae, and geraniums ; and 
the birds began to lay their eggs. Numerous Lamellicorn and 
Heteromerous insects, the latter remarkable for their deeply 
sculptured bodies, were slowly crawling about; while the lizard 
tribe, the constant inhabitants of a sandy soil, darted about in 
every direction. During the first eleven days, whilst nature 
was dormant, the mean temperature taken from observations 
made every two hours on board the Beagle , was 5 10 ; and in 
the middle of the day the thermometer seldom ranged above 
5 5°. On the eleven succeeding days, in which all living things 
became so animated, the mean was 58°, and the range in the 
middle of the day between sixty and seventy. Here then an 
increase of seven degrees in mean temperature, but a greater 
one of extreme heat, was sufficient to awake the functions of 
life. At Monte Video, from which we had just before sailed, 
in the twenty-three days included between the 26th of July 
and the 19th of August, the mean temperature from 276 
observations was 5 8°.4 ; the mean hottest day being 65°. 5, and 
