Characteristics of Whales. 9 
of the hind-limbs, but there is no evidence that this is really the 
case. 
The skull is modified in a peculiar manner; the brain-case 
being short, high, and broad, and, in fact, almost spherical. The 
nostrils open upwards, immediately in front of the brain-case, and 
before them is a more or less horizontally prolonged beak, extending 
forwards to form the upper jaw or roof of the mouth. Other 
particulars in regard to the structure of the skull are given under 
the heading of the Pilot-Whale (p. 37). There are no collar- 
bones (clavicles). The upper arm-bone, or humerus, is freely 
moyable on the blade-bone, or scapula, at the shoulder-joint ; 
but beyond this the articulations of the limb are imperfect, 
flattened ends of the bones coming in contact with each other, 
with fibrous tissue interposed, allowing scarcely any motion. 
The two bones of the fore-arm (radius and ulna) are distinct and 
much flattened, as are also the bones of the hand. There are 
usually five fingers in the skeleton, though sometimes the first, 
corresponding to the thumb, is wanting. The pelvis, or hip-bone, 
is represented merely by a pair of elongated slender bones, 
suspended below, and at some distance from, the vertebral column, 
in the region of the loins; and to the outer side of these, in some 
Whales, are attached small bones representing the bones of the 
limb proper. Thus the exhibited skeleton of the Common 
Rorqual shows a little nodule of bone, scarcely larger than a 
walnut, which is the rudiment of the thigh-bone, or femur, and 
is the only trace of a hind-limb this gigantic animal possesses. 
Cetaceans abound in all seas, and some Dolphins are inhabitants 
of the larger rivers of South America and Southern Asia, They 
pass their life entirely in the water, as on land they are absolutely 
helpless; whether they sleep is unknown. They have to rise 
frequently to the surface in order to breathe; and, in relation to 
the constant upward and downward movement in the water thus 
necessitated, the tail, unlike that of a Fish, whose movements are 
mainly in straightforward or lateral directions, is expanded hori- 
zontally. The position of the nostrils on the highest part of the 
head is important for this mode of life, as it is the only part of the 
body the exposure of which above the surface is necessary. 
The ‘ spouting,” or “blowing,” of Whales is the ordinary act of 
breathing, performed at longer intervals than in land-animals. 
The moment a Whale rises to the surface it forcibly expels from 
its lungs the air taken in at the last inspiration, which is heated 
