Cetacea constitute a group of mammals in which the soft tissues have been studied only superficially. The size of these mammals and the conditions under which they are caught make proper preservation of their bodies for dissection almost impossible, not to speak of the difficulty of actual shipment to a laboratory and subsequent storage there. Moreover, in the case of most of the larger whales, so much time elapses between the killing of the animals and the completion of an autopsy that, even in the field, it is difficult to obtain the viscera fresh and properly fixed. The magnitude of such an undertaking is described by Turner. At Longniddry, in 1872, he helped to cut up a great stranded finner whale which was 78 feet, 9 inches long, from which a fetus measuring 19 feet, 6 inches was removed. The dolphins or porpoises constitute the smallest of the whales. They