AbstractsBiology & Animal Science

A series of studies have been made in both rats and guinea pigs with respect to their oxygen consumption, and the results are reported. The controlvalues of the metabolic rates observed in 360 normal guinea pigs and 136 normal rats were treated statistically. For guinea pigs, the mean was153.98 1 0*274, with a standard deviation of 18.97. For rats, the values were 175.06 * 0.577; S. D. 19.08. Female rats were found to have lower andsteadier rates than males, but in guinea pigs there was no significant difference. A small rythimic seasonal variation of less than = 5$ wasobserved in the normal metabolic rates of guinea pigs, when they were kept in a constant temperature room. In a small series of guinea pigs fastingfor 24 and 48 hours raised the metabolism above normal. For this reason, food was not removed from the cages during experiments. The effect ofcooling the environment for short periods was observed, and the response was found to be very regular, amounting to an increase of 13-14$ perdegree C fall in external temperature.