Prolonged severe anaemia may reduce the level of muscle hemoglobin slowly. If the original level was high the reduction may amount to 30-40%. If dogs are healthy and active this reduction scarcely goes below 400-500 mgm. muscle hemoglobin per 100 gm. Even lower normal values may occur in quiet house dogs. Exercise is more important than anemia in determining the muscle hemoglobin level in the dog. Anemia demands can not rob the striated muscle of its hemoglobin; muscle hemoglobin maintenance is on a par with the need for blood hemoglobin. This shows the importance of muscle hemoglobin in body economy and in general pigment metabolism. Muscular paralysis (sciatic nerve section) is followed by a fairly rapid loss of muscle hemoglobin which becomes more noticeable from week to week. After 7 weeks some muscles may contain only 1/2 the normal muscle hemoglobin.