Some histological effects of ultrasonic waves on cells and tissues of the fish lebistes reticulatus and on the larva of rana sylvatica

Some pathological effects of supersonic waves produced by the piezo‐electric oscillator described by Wood and Loomis ('27) are described. Death of fish and frogs was due to haemolysis of erythrocytes within the gill capillaries. Disruption of gill filaments, trauma, and extravasation in the head and gill region and in the peripheral musculature were noted. No effect on the nervous system was apparent histologically. Organisms were not killed in water under hyper‐ or hyponormal pressures. In these cases no cavitation of gases took place. Isolated frog sartorius muscle in Ringer's was not damaged. Bubbles of gas were easily observed within the muscle cells of the tadpoles when such cells were not more violently disturbed. Such bubbles were abundant in the more fluid muscles of four‐ or five‐day tadpoles, less abundant in 15‐ to 35‐mm. Lebistes, and entirely lacking in adult frog sartorius. Protoplasmic viscosity differences probably explain the gradient. The above‐observed intracellular cavitation explains the muscular destruction, the haemolysis, the change in specific gravity of organisms subjected to the wave treatment, and may offer light upon the stimulatory effect of such waves on excitable tissues (compare Harvey, '28).