In the full-grown creature the skull will measure at least twenty feet in length. Unhinge the lower jaw, and the side view of this skull is as the side of a moderately inclined plane resting throughout on a level base. But in life⁠—as we have elsewhere seen⁠—this inclined plane is angularly filled up, and almost squared by the enormous superincumbent mass of the junk and sperm. At the high end the skull forms a crater to bed that part of the mass; while under the long floor of this crater⁠—in another cavity seldom exceeding ten inches in length and as many in depth⁠—reposes the mere handful of this monster’s brain. The brain is at least twenty feet from his apparent forehead in life; it is hidden away behind its vast outworks, like the innermost citadel within the amplified fortifications of Quebec. So like a choice casket is it secreted in him, that I have known some whalemen who peremptorily deny that the Sperm Whale has any other brain than that palpable semblance of one formed by the cubic-yards of his sperm magazine. Lying in strange folds, courses, and convolutions, to their apprehensions, it seems more in keeping with the idea of his general might to regard that mystic part of him as the seat of his intelligence.