Comparison of capillary density in skeletal muscles of animals differing in respect of their physical activity--the hare (Lepus europaeus), the domestic rabbit (Oryctolagus domesticus), the brown rat (Rattus norvegicus) and the trained and untrained rat.

Adaptation, Physiological Animals Behavior, Animal Biological Evolution Body Weight Capillaries/anatomy & histology,physiology Densitometry Muscles/blood supply,physiology Organ Size Physical Exertion Rabbits Rats Species Specificity