106 
CETACEAN GALLERY. 
filled with oil. In the vertebral column the region of the neck 
is remarkably short and inca])able of motion, and the vertebrae, 
originally seven in number, as in other mammals, are in many 
species more or less fused together into a solid mass. None of 
the hinder vertebrae of the body are united together to form a 
“ sacrum or to join the pelvis, as in mammals in which the hind 
limbs are fully developed. The lumbar and caudal vertebrae are 
numerous and large, and capable of very free motion in all direc- 
tions. Beneath the latter are large chevron bones which pro- 
ject downwards, and give increased surface for the attachment of the 
powerful muscles that move the tail. There are no bones sup- 
porting the lateral “ flukes ” of the tail or the dorsal fin. 
The skull is modified in a peeuliar manner. The brain-case is 
short, high, and broad, almost spherical in fact. The nostrils open 
upwards, immediately in front of the brain-case, and before them 
is a more or less horizontally prolonged beak or rostrum, ex- 
tending forwards to form the upper jaw or roof of the mouth. In 
detail the form of the skull varies much in different groups. 
There are no collar-bones or 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 forearm (the radius and ulna) are 
distinct and very much flattened, as are all the bones of the hand. 
There are usually five fingers, though sometimes the first, or that 
which corresponds to the thumb of man, is wanting. The pelvis 
or hip-bone is represented by a pair of elongated slender bones, 
suspended below, and at some distance, from the vertebral eolumn, 
in the region of the loins. As these bones are in the living animal 
concealed in the flesh and not connected with the spinal column, 
they are olten lost in preparing the skeletons, and hence are 
absent in many of the sj)ecimeus in the Gallery. To the outer 
side of these, in some AVhales, small bones are attached which 
represent the bones of the limb proper. In the great skeleton of 
the Rorqual (Balcenopiei'a mysciihis), at the further end of the 
Gallery, a little nodule of bone, scarcely larger than a walnut, has 
been fortunately preserved. It is the rudiment of the thigh-bone 
