On the corpora allata of dipterous insects. II

Abstract

In an earlier paper (Burtt 1937) it was suggested, on morphological and histological evidence, that Weismann’s ring in the larva of Calliphora represents the modified corpora allata. Fraenkel (1935) had previously found that pupation in Calliphora is induced by a hormone which is secreted in the region of the central nervous system. Accordingly, I suggested that Weismann’s ring was the organ responsible for this effect. Simultaneously with the appearance of my paper, Hadorn (1937 a ) published experimental evidence on the function of Weismann’s ring (“ ring gland”) in the larva of Drosophila melanogaster , and came independently to the same conclusion as myself regarding the significance of the ring. Hadorn used the technique of Ephrussi and Beadle for transplantation in Drosophila larvae. In his first paper, Hadorn (1937 a ) describes the results of experiments on the mutant “ lethal giant”—a form in which pupation is either greatly delayed or absent, and the larva reaches a size exceeding the normal.