Diffusion Phenomena in the Tracheae of Phormia Larvae

I N STUDYING the cutaneous respiration of larvae of Phormia regina, we observed that larvae submerged for 6 hours in oxygenated water and then returned to air were at first able to move about but died within a few hours, while those submerged for 6 hours in aerated water and then returned to air showed at first no pulse, intestinal peristalsis, or body movement but eventually recovbags were exposed to a gas or submerged in water saturated with the gas. They were then removed at intervals and examined with a dissecting microscope. In other experiments we used the arrangement pictured in Figure 1, in which larvae were induced to crawl serially into a glass tube of bore slightly greater than the larval diameter and were separated by screen-ended spools. Three such larvae could be conveniently kept under ob-