1. The proximal regions of the Malpighian tubules of Drosopbila funebris and Calliphora erythro cephala are supplied with systems of circular and longitudinal muscles external to the basement membrane.
2. These muscles are continuous with those of the mid-gut.
3. There is a terminal muscle to each anterior tubule in Drosophila funebris connected to the alar muscles of the pericardial septum.
4. Peristalsis has been observed in the proximal regions of the tubules, caused by the circular muscles.
5. The tubules exhibit a waving movement, probably due to the longitudinal muscle-bands of the lower or proximal ends of the tubules.
6. Calcium carbonate is stored in the terminal portions of the anterior tubules of Drosophila funebris.
7. This calcium carbonate is not eliminated at the beginning of metamorphosis, but is passed to the gut about the sixth day of pupal life, and is only expelled from the body on the emergence of the adult.
8. Calcium carbonate is found in the Malpighian tubules of the adult Drosophila funebris.