SOME OBSERVATIONS ON THE GOLGI MATERIAL IN THE LARVAL EPIDERMAL CELLS OF DROSOPHILA MELANOGASTER

¹ University of Washington, Seattle, Wash.

1. On the strength of observations set forth in the following paragraphs, it has been concluded that the epidermal cells of Drosophila larvae seem to act as internal secretion organs, at least at the age when the larvae are about one day before pupation.

2. The relation of the Golgi bodies to the globules, both inside and outside of the Golgi bodies as observed in the epidermal cells, has been found to be the same as what has been established in cells definitely known to be of a glandular nature in the larvae of this fly. In each piece of Golgi material, a single droplet is seen to make its first appearance and gradually to increase in size, eventually breaking free from the confining Golgi shell. It seems to be the normal procedure for the free separate secretory droplets to coalesce to form big vacuoles; and their further confluence gives to the cells in advanced secretory synthesis an extremely vacuolated appearance.

3. Many epidermal cells have been found with their cell membrane broken, thus releasing their secretion product into the body cavity of the larva. The apparent healthy condition of the nuclei of such cells and the absence of replacement cells in the epidermis would point to a merocrine mechanism of secretion in this case.