Some years ago the British Association for the Advancement of Science standardised the methods for the determination of the measurements of length, breadth, and height of the living head or dead skull, but said nothing about the brain. But to-day we know that these same methods can also be used for the measurement of the post-mortem brain. The advantages of having one common series of measurements for the living head, dried skull, and post-mortem brain, and one standard mode of comparing the results are so obvious as to need no further justification.