Temperature sensitive experiments on the interaction of Abruptex mutations of the Notch locus and Enhancer of split indicate that the effect of temperature on the development of macrochaeta and wing venation is different. This suggest that Notch affects the development of macrochaeta and wing venation in different and independent ways being in accordance with the proposition that the signal pathway from the Notch receptor at the cell membrane to Enhancer of split complex in the nucleus is different in the case of the development of macrochaeta and wing venation. The Abruptex mutations as gain-of-function mutations of the Notch locus cannot rescue the Enhancer of split phenotype.