The Effects of Ultrasonic Treatment on Embryonic Development of Drosophila melanogaster

Abstract

The work of Seidel and his school (reviewed Seidel, 1935, 1936) showed that embryonic development within the class Insecta ranges from the indeterminate or regulative type in the Odonata to completely determinate or mosaic development in the Diptera. Between these two extremes are insects in which the developmental fate of the egg is not determined at the time of fertilization, but which becomes determined at varying times afterwards. Actually the scale is a relative one, for development eventually becomes completely determined in the Odonata, and there is experimental evidence (Howland & Sonnenblick, 1936) which suggests there is some regulative power in the Dipteran egg prior to fusion of the gamete nuclei. Éxperimental methods used to such great advantage in studies of vertebrate development cannot be used in studying the insect egg, as the turgor pressure and fluidity of the egg contents make transplantation studies and the culturing of embryonic tissues in vitro impossible in most forms.