The relation of blood volume to body weight and arterial haemoglobin levels in rabbits.

1. Relative blood volume (ml./kg) of rabbits calculated from total circulating haemoglobin and blood haemoglobin concentration decreases rapidly during the first few weeks of life and more slowly thereafter.2. In anaemic rabbits over 1 kg body weight, relative blood volume is significantly increased.3. Rabbits under 1 kg body weight have larger blood volumes than would be expected from their anaemia alone, were the relationship deduced in rabbits over 1 kg in body weight applicable. Blood volume was not related to haemoglobin concentration in these immature rabbits.