The Structure of the Ring-Gland (Corpus Allatum) in Normal and Lethal Larvae of Drosophila Melanogaster

Abstract

For the secretory activity of the ring-gland cells (pupation hormone) as suggested by Hadorn (1937) no histological evidence could be established. The ring-gland, or at least its greater part (large cells), is homologous to the corpora allata found in other insects. The question of a homology between the small ring-cells and the corpora cardiaca (Pflugfelder) is discussed. During the larval development of Drosophila the growth of the ring-gland (corpus allatum) takes place by an increase in the size of the cells. In the grown-up lgl-larvae the ring-gland as well as its cell elements is considerably smaller than normal. Retardation in puparium formation of the lgl-larvae is apparently due to under-development of the corpora allata.