84 
WHALE ROOM. 
fat, held together by a mesh of fibrous tissue^ constituting the- 
blubber,^’ which serves the purpose of the hairy covering of 
other Mammals in retaining the heat of the body. In most 
species there is a fin, more or less triangular in shape, composed 
only of skin and fibrous tissue, near the middle of the hack,, 
which assists in keeping the animal upright when swimming. 
The eye is small ; and the aperture of the ear minute, and 
without vestige of a pinna or conch. The nostrils, generally 
called blow-holes,^^ open separately, or by a single valve-like 
aperture, placed (except in the Sperm-Whale) not at the- 
extremity of the snout, but near the top of the head. 
The bones generally are spongy in texture, their cavities 
being filled with oil. In the backbone the region of the neck 
is remarkably short and incapable of motion, and the vertebrae,, 
originally seven in number, as in other Mammals, are in many 
species more or less fused into a solid mass. All the hinder 
vertebrae of the body are free ; none being united to form a 
“sacrum,’^ or joining the pelvis, as in Mammals in which the hind- 
limbs are fully developed. The vertebrae of the loins and tail are 
numerous, large, and capable of free motion. Beneath the latter 
are large V-shaped “ chevron-bones which project downw^ards, 
and give increased surface for the attachment of the muscles 
which move the tail. There are no bones supporting the lateral 
“ flukes ” of the tail or the back-fin. 
The skull is modified in a peculiar manner, the brain-case 
being short, high, and broad — almost spherical, in fact. As a 
rule, the nostrils open upwards, 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. 
There are no collar-bones (clavicles). The upper arm-bone or 
humerus is freely movable on the scapula, or blade-bone, 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 of 
scarcely any motion. The two bones of the fore-arm (radius 
and ulna) are distinct and much flattened, as are the bones of 
the hand. There are usually five digits, though sometimes the 
number may be reduced to four. The pelvis, or hip-bone, is 
