THE GREENLAND WHALE. 79 



the roof of the mouth. They enclose the tongue 

 betAveen their lower extremities, and are themselves 

 covered by the lower lip. There are upwards of 

 three hundred of these plates on each side of the jaw, 

 resembhng a frame of saws in a saw-mill; they 

 are longest in the middle, whence they gradually 

 diminish away to nothing both in front and behind : 

 ten or twelve feet is their usual length. In the 

 youngest whales, called suckers, the baleen is only a 

 few inches long ; when the length reaches six feet 

 or upwards, the whale is said to be size : a large 

 whale sometimes pelds a ton of baleen. 



As the formation of the baleen is curious, and 

 forms the most striking peculiarity in this and the 

 next genus, we shall supply some details concern- 

 ing its foi-mation, principally taken from the account 

 of Mr. J. Hunter. This singular production does 

 not proceed directly from the gum itself, but from a 

 thin vascular substance resting upon it. This sub- 

 stance, which may be called the nidus of the baleen, 

 sends out a thin broad process, answering to each 

 plate, on which the plate is formed ; so that each 

 plate is necessarily hollow at its gro^^ing end, the 

 first part of the groAvth taking place in the inside of 

 this hollow. Besides this, the plate receives addi- 

 tional layers on the outside, which are formed in the 

 same vascular nidus as it extends along the jaw. 

 This part forms a semi-homy substance between 

 each plate, which is very white, rises with the whale- 

 bone, and becomes even with the outer edge of the 

 jaw. This intermediate substance fills up the spaces 



