OF THE SPERM WHALE. 
79 
of which form the large posterior portion of the skull, is 
situated the cavity in which the brain is lodged in the 
living animal : it is continuous with the spinal canal of 
the vertebrae, and measures only in width about 14 
inches, in length 10 inches, and in depth 9 inches. 
On the left side of the base of the skull, near the root 
of what may be termed the vomer, there is a foramen for 
the transmission of the blowing-tube. It perforates the 
floor of the crater-like cavity, which is only about three 
inches in thickness, and in the recent animal the spiracle 
passes through the soft parts of the junk and case, and 
terminates at the anterior upper angle of the head. This 
foramen is nearly round? and is 8| inches in diameter. 
The bones of the cranium, although very strong, are 
still porous and light. 
OF THE LOWER JAW. 
The lower jaw is 16 feet 10 inches long, and forms, in 
its whole length, a slight arch, with the convexity down- 
wards ; it is armed with forty-eight formidable teeth, 
twenty -four on each side. The lower jaw is formed of 
two lateral pieces, which form a cylindrical symphysis 
anteriorly, for 10 feet 5 inches of its whole length, which 
is at its posterior junction 11| inches in diameter, and 
at its anterior and smallest end 1 \ inches in diameter, 
the whole of which is formed of a dense and very 
•strong kind of osseous structure. At 10 feet 5 inches 
from its anterior extremity, it divides and forms two 
lateral branches, which rapidly expand in width, and go 
