DEVELOPMENT OF WHALES

Marlborough Express, Volume XLVII, Issue 14, 17 January 1913, Page 2

DEVELOPMENT OF WHALES

I The study of fossils and embryos has ! succeeded in proving, says Professor - Jvukenthal, the foremost authority on j cetaceans, that whales are descended from ancient land beasts of prey—the , creodonts. In the long process of ; evolution changes have been wrought : which enable these monster mammals to handle themselves in the water with as much ease as if they were veritable fishes. The ombryo in its first developmen tis built after the type of a land mammal ; the head is clearly separated from the body by a neck, the jaws are equipped with a full set of teeth, what would be the limbs are plainly indicated, and there is reason to believe that at one stage the embryo is covered with a coat of fur. Life in the water first caused a slow decrease of specific weight, giving the whale gradually the ability to float on the surface. This was brought about principally by the accumulation of a thick layer of fat under the skin, and the growth of air-spaces in the enormous skull, which in some whales measures a third of the entire body The incredible speed that the de-

velopment of the powerful tail-fia-made possible, caused the elimination!of all projecting organs that might increase friction. Thus the spindleshaped body is perfectly smooth; onlj on its back is generally a narrow projection, which acts as a keel. Diving also has had its influence on the alteration of the body. Sometimes, as in the case of the largetoothed whales that feed on cuttlefish, they go to a depth of a thousand yards or more. The openings of the body then close tight, to resist increasing pressure. Nature has provided the nose with a vurious valve arrangement, the little eye is surrounded by a covering as hard as iron an dfortified by powerful muscles and the whole body is protected by a tremendous covering of fat. With these curious changes has come an enormous increase in size, until the whale, which descended from a. comparatively small animal, is now: the largest that lives, for its weight not uncommonly reaches sixty or seventy tons. It would seem impossible for the mother to provide the young whale with unwatered milk, but evolution! has solved the problem in this wise: the milk is first collected in a container m the mother's body, and then! by a specially adapted muscle it is squirted directly into the baby's mouth without coming in contact with! the sea-water.