I have, as personal evidence upon this subject, the fact that a blue whale, harpooned between the shoulders and but slightly injured, dove straight downward and took out over a quarter of a mile of rope. We were, at the time, almost a hundred miles at sea and so far as could be determined the animal had gone down to the full limit of the line which hung from the bows as rigid as a bar of steel. The whale remained below for thirty-two minutes and reappeared not more than a hundred yards away and directly in front of the ship. It is the opinion of every whaler with whom I have talked that all the large cetaceans can descend to a considerable depth, and each man will give numerous instances, similar to the one I have cited in the case of the blue whale, to prove his point. Until further information is available this subject must be an open one. A smooth, circular patch of water is always left at the spot where a large whale dives. This is undoubtedly produced by suction and interrupted wave action but has given rise to many ingenious and absurd theories in explanation. When studying whales the most important fact to remember is that _they are one-time land mammals which have taken up a life in the water_ and that their bodily activities, although somewhat modified, are nevertheless essentially the same as those of a horse, cow, or any other land mammal. Since a whale breathes air, when it is below the surface the breath must be held, for if water should be taken into the lungs the animal would drown. Thus, as soon as a cetacean comes to the surface its breath is expelled and a fresh supply inhaled before it again goes down, just as in the case of a man when diving. However a whale is able to hold its breath for a much longer time than can an ordinary land mammal—even as much as forty-five minutes or an hour. When the animal comes to the surface the breath which has been contained in the lungs under pressure is highly heated, and as it is forcibly expelled into the colder outer air it condenses, forming a column of steam or vapor. A similar effect may be produced by any person if, on a frosty morning, the breath is suddenly blown out of the mouth. I have often seen a whale blow when its head was still a short distance under the surface and at such times a little water will be thrown upward with the spout. [Illustration: The tail of the humpback as the animal “sounds” looks like a great butterfly which has alighted upon the water. ] That whales spout out of the blowholes water which has been taken in through the mouth is probably more widely believed than any other popular misconception. As a matter of fact such a performance would be impossible because a whale’s nostrils do not open into the back of the mouth as do those of a man, and the animal is not able to breathe through its mouth as do ordinary land mammals.