I have to say a few words to you this afternoon on the Registers of the Human Voice. My definition of the registers is this :—A register consists of a series of tones produced by the same mechanism. If we were to hear two men outside playing a scale, one commencing on a double bass, and the other continuing, say, on a violoncello, without the scale being interrupted, we should know exactly where the one left off and where the other one came in. In a similar way several series of tones are produced by different mechanisms in the human voice, and each of such series I term a register; the mechanism of some of the registers may be seen just the same as the tones of these registers may be heard.