I02 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 15 th a 

 few animals began to appear, and by the i8th (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 51°; and in 

 the middle of the day the thermometer seldom ranged above 

 55°. 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 58°.4; the mean hottest day being 65°. 5, and 



