He went on to say that his mate had fallen in before, and on his helping him into the boat, it had been nearly capsized, and that, as neither of them could swim, he did not wish to be drowned as well as his companion. The attitude which the human body assumes in the sidestroke, also more closely approximates to that form than it does in any other style of swimming. The actual resistance of the medium in which he is moving, which is augmented in the ratio of the square of the speed. The increased space which he has to cover in each unit of time, which is increased in the ratio of the speed. The resistance which the water offers depends upon the velocity of the stroke, and the impetus which the body receives is regulated by the combined influence of the velocity and direction of the stroke.
Land animals require a much greater proportion of bone than the inhabitants of the water.
In the former, as the entire support from the ground when standing is received through the feet, a framework of considerable strength and rigidity is required to maintain the body erect. Fishes have their support distributed over so great a portion of the body, that they can dispense with the strong framework requisite for the support of most land animals. Since they can dispense with these passive organs of locomotion, the bones, they have more room for the active ones, the muscles. Therefore, to their superior muscular development, as well as to their shape and great flexibility, is to be attributed their superior speed in the water. Steedman on the North American Indians Steedman describes the alternate continuous arm action used by the Mandan Indians, which indicates that these natives of North America were using what was in effect a type of crawl stroke long before it was developed in Western culture.