Beschreibung:
<jats:title>ABSTRACT</jats:title>
<jats:p>Narcosis and asphyxia in insects can be investigated by measuring the recovery time. This and other terms are defined, and suitable criteria of recovery are given. Simple techniques for the etherizing and gassing of Drosophila batches are described and the validity of the quantitative results obtained is shown. The recovery time is increased by the time of influx and by the concentration oj the narcotic. The shapes of the curves obtained in experimental Series are logarithmic (carbon dioxide asphyxiation), straight line (ether in some species), concave, convex or sigmoid (ether). It is suggested that the different forms of ether recovery curves are different parts of essentially similar curves, which one might explain by the joint action of two macrophases, one aqueous and one lipoid. Physiological factors determining recovery times are : (a) sex : females recover earlier from ether narcosis than males; (b) age: young flies recover earlier than older ones; (c) lack of food and moisture, which increases the recovery time ; and (d) chemical reaction: flies kept on acid food remain longer narcotized than flies-bred on an alkaline medium. Carbon dioxide lengthens recovery from ether narcosis and hydrocyanic acid immobilization when applied before the influx time and shortens it when applied during recovery-time. If administered during recovery, it also shortens the recovery from asphyxiation. Carbon monoxide and coal gas administered before narcotization can shorten the recovery time from ether narcosis. Under specified conditions corresponding to those, used during narcosis by Droso-phila-workers some differences in recovery time after etherization due to genetical differences could be established. Significant differences also exist between some Drosophila species, races and mutants in their resistance to carbon dioxide, asphyxiation and hydrocyanic acid.gas.</jats:p>