From 4 to 5 feet long. It lives in "schools," or companies, and pursues the herrings and mackerel.
The Sperm-whale, or Cachalot, may serve as our type of the toothed whales. It attains to the same great dimensions as the largest of the whalebone group. A more active animal for its size could scarcely be conceived; and I have seen one, in the Indian Ocean, fling itself three or four times in succession out of water like a salmon, striking the surface each time as it fell back with a report like that of a gun. No one appears to have explained whether performances of this sort are due to mere playfulness, or, as seems more probable, to the attacks of parasites or such larger enemies as sharks or "killers." I have also seen four thresher-sharks leaping out of water, and falling with a loud blow on the whale's back; but the victim lay quite still in this case, and may in fact have been worn out before we came upon the scene. I wish to add that I took the word of the skipper, himself an old whaling-captain, for their identity as threshers. The dazzling sun shone full on them, and on the sea between, and it was impossible, even with the ship's telescope, to recognise them with any accuracy. The cachalot has a very different profile from what any one who had seen only its skull in a museum would be led to expect, for the sperm-cavity in the forehead is not indicated in the bones. The structure of the head enables the animal to drop the lower jaw almost at right angles to the upper; and Mr. Frank Bullen quotes, in his fascinating "Cruise of the Cachalot," the current belief that it does so to attract its prey by the whiteness of its teeth and palate. Although both fishes and cephalopods are very curious, even to their own destruction, it is doubtful whether the whale could not catch its food more rapidly by swimming open-mouthed through the acres of floating squid encountered all over the warmer waters of the ocean.
Photo by A. S. Rudland & Sons.
ELLIOTT'S DOLPHIN.
One of the commoner Indian species.
Photo by A. S. Rudland & Sons.
RISSO'S DOLPHIN.
About 13 feet in length, found in almost all oceans.