It would be interesting to know how long sperm whales live. The bull which was killed in Japan for the American Museum showed unmistakable evidences of great age. Its head was covered with white crisscrossed scars, bearing testimony of terrific battles with giant squids in the ocean depths, and the teeth of its lower jaw were worn almost flat, projecting only an inch or two above the gum. The bones of its skeleton were hard and rough, being covered with tubercles and bony growths. [Illustration: A posterior view of the head of the Museum’s sperm whale. The thick covering of blubber which encircles the head is well shown. ] All this indicated that the animal had lived for many years, but how many it is impossible to tell. The condition of the skeleton shows whether a whale is old or young, for in immature animals the bones of the skull are separated (i. e., the sutures are open), the plates on the end of the vertebræ (epiphyses) are free, and all the bones are soft and spongy. Even though the whale may have reached adult size, which it usually does in three or four years, the evidences of youth are still present in the skeleton. Reasoning by analogy (which is always unsafe), I have come to the conclusion that a whale’s life is well within one hundred years, but I must admit that my argument is mainly theory and that there are but few facts with which it may be supported. Until recently, many naturalists held the view that whales lived for hundreds of years and that they did not reach adult size until long after birth. The latter contention has been proved utterly wrong, but of the former we have little new knowledge; neither do I see how we can ever estimate a whale’s age with any degree of accuracy. CHAPTER XX A DEEP-SEA SPERM WHALE HUNT Every time I see a sperm whale shot with a bomb harpoon from the bows of a steamship, I have more respect for the old-time hunters who kill the huge brutes with a hand harpoon and lance. The vitality of a sperm is enormous, and even when several bombs have exploded in its body the animal will often fight for hours before it spouts blood and dies. When Captain Olsen secured the sixty-foot sperm, the skeleton of which was sent to the Museum, he got fast with one iron but did not kill the whale. After some time the vessel was near enough for a second shot, and Olsen fired a harpoon which was bent slightly upward at the point. The heavy iron, instead of penetrating the blubber, rebounded, and when it was drawn back by the winch was found to be actually bent double, the point of the bomb being within a few inches of the opposite end. It required three harpoons, each weighing one hundred and ten pounds, to finish the whale.