92 BAHIA BLAXCA. [CHAP. v. 



multimaculatus) remarkable from its habits. It lives ou 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 hibernation 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 15th, 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, cenotherse, and geraniums ; and the birds began to lay 

 their eggs. Numerous Lainellicorn 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 60 and 70. 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 the coldest 46. The 

 lowest point to which the thermometer fell was 41 0> 5, and occa- 

 sionally in the middle of the day it rose to 69 or 70. Yet with 

 this high temperature, almost every beetle, several genera of 

 spiders, snails, and land-shells, toads and lizards were all lying- 

 torpid beneath stones. But we have seen that at Bahia Blanca, 



