Tolerance of small animals to acceleration.

Mice, rats, rabbits, finches, pigeons, and roosters were exposed to +Gz, minus Gz, and minus Gx inertial forces due to acceleration. The range of body weight of all animals was from 14 g to 1.6 kg. The magnitude of G and duration of exposure time were within 130 G and 20 min and the average rate of changes of G was 2.8 G/s. The G tolerances of these animals were compared with one another at 50% mortality. The tolerance of each species was expressed as the area under the tolerance curve. Changes of tolerance were obtained by the changes of direction of G force. The tolerance ratio of minus Gz to +Gz force was 0.58 and that of minus Gx to +Gz was 2.12. Body weight was inversely related to the threshold G-value at which animals are resistant to the prolonged acceleration.