Read it through once

Ere this, you must have plainly seen the truth of what I started with—that the Sperm Whale and the Right Whale have almost entirely different heads. To sum up, then: in the Right Whale’s there is no great well of sperm; no ivory teeth at all; no long, slender mandible of a lower jaw, like the Sperm Whale’s. Nor in the Sperm Whale are there any of those blinds of bone; no huge lower lip; and scarcely anything of a tongue. Again, the Right Whale has two external spout-holes, the Sperm Whale only one.