anatomy ot the whale. 
153 
which is the seat of a muscular substance, attached 
by its anterior extremity to the surface of the skull, 
and also attached by its posterior and inferior extre¬ 
mity to the interior of the skull, at some depth in 
the blowing canal ci a. The part of this muscle that 
penetrates the bony canal, is of a conical form, the 
apex downward or within, represented at b, in the 
annexed figure of a vertical section of the skull; 
so that when this interior portion contracts, the 
muscular cone b, is drawn tight into the orifice, 
and completely closes the breathing-canal a a; 
while, on the other hand, the action of the external 
part of the muscle, draws the conical plug forward 
and upward, and affords a free passage for the air in 
respiration. This beautiful structure it is, (aided. 
