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 degrees; and in the middle of the day the thermometer seldom ranged above 55 degrees.

On the eleven succeeding days, in which all living things became so animated, the mean was 58 degrees, 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 degrees; the mean hottest day being 65.5 degrees, and the coldest 46 degrees.

The lowest point to which the thermometer fell was 41.5 degrees, and occasionally in the middle of the day it rose to 69 or 70 degrees.
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.