On the Bionomics of the Vinegar Eelworm

Abstract

From considerations of previous work on the vinegar eelworm, and from the writer's experiments, it is concluded that:I.—Concerning physical and chemical stimuli:(a) The worm has very little need of oxygen, but displays a negative geotaxis which is independent of dissolved oxygen as a stimulus.(b) It tolerates temperatures between 0° and 35°, can survive short intervals at 20°, and can live for several days at 37°. It is practically indifferent to light.(c) The worm and its larvæ are very susceptible to drying, surviving only a few minutes a thorough desiccation from water.(d) The toleration limits for hydrogen ion concentration are pH: 1·6 on the acid side and about pH : 11 on the alkaline side.(e) So far as can be ascertained, the worm tends to make the medium in which it lives slightly but permanently more acid than it would otherwise be.(f) It is very sensitive to iodine, ammonia and chloroform, but is extraordinarily resistant to most chemical substances, including acidity indicators and buffer solutions.(g) It can be grown in most culture media, and has been cultured aseptically by Zimmermann, who finds that either bacteria (living or dead) or an unknown substance from the autolysate of yeast is essential as food.