Abstract
Adult roundworms (Ascaris lumbricoides) obtained from pigs were suspended in modified Tyrode solution at 37 degrees in fine nylon stockings, and the movements of the stockings were recorded. This method of suspension avoided damage to the cuticle or occlusion of the alimentary tract of the worm.Piperazine salts caused gradual narcosis, the time of onset of which was related linearly to the logarithm of the concentration of drug in the bath. The method is suitable for the assay of preparations of piperazine. Tetrachlorethylene, hexylresorcinol, and oil of chenopodium all caused stimulation of movement before the worm was immobilized. Santonin caused incoordination of the movements of the anterior end of the worm; the movements of the body were apparently unaffected. Piperazine is the safest preparation available for the treatment of ascariasis.