Page:Natural History (1848).djvu/113

Rh Mammalia are, would require protection against the rapid abstraction of heat from the body. Fat being a slow conductor of caloric, the envelopment of the whole body in a thick "blanket," as it has been termed, of this substance, retains the generated heat, and keeps the animal warm at the lowest temperature. Being lighter than water, it also greatly contributes to the buoyancy of the body. A dead Whale floats, but the carcase, when stripped of the blubber, sinks with precipitation.

Thus the whole organization of the Cetacea and its perfect adaptation to a sphere of actions, and to habits, very different from those common to the Mammalia, displays very numerous, striking, and unexpected examples of the infinite wisdom and goodness with which the Almighty God has made all His works. And surely the observation of such displays, and the awakening of our praises to Him, should be the first objects of scientific studies. The genera which are usually placed in this Family, differ from each other in so many particulars, that their characters are rather negative than positive. They agree in having the head of moderate size, as compared with other Mammalia: the muzzle usually projects more or less, in the form of a slender beak, the jaws are for the most part both furnished with teeth, very numerous, and conical in form; but are devoid of baleen or whalebone. The blow-hole is single, of