Abstract
Using these concentrations of ether (1 per cent, 3.65 per cent, 7.3 per cent), the following conclusions may be drawn. 1. The first effect of ether is to cause a depression in the rate of respiration. This is followed by a rapid rise above normal, which in turn is succeeded by a fall. 2. With all these concentrations the respiration is ultimately reduced to approximately the same level; the stronger the ether, the less time required to produce this result. 3. Even when the respiration has been reduced below normal, recovery is possible on removal from the ether, and appears to be complete, if sufficient time is allowed. If, however, the rate has been too far depressed, no recovery is possible. 4. These results extend those of Irwin on frog eggs and Fundulus embryos.