82 HISTORY OF THE WHALE. 



from the upper jaw and sides of the crown-bone. The 

 plates of baleen are generally curved longitudinally, and 

 give an arched form to the roof of the mouth. They enclose 

 the tongue between their lower extremeties, and are them- 

 selves covered by the lower lip. There are upwards of 

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

 resembling 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 yields 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 concerning its formation, princi- 

 pally taken from the account of Mr. J. Hunter. This singu- 

 lar production does not proceed directly from the gum 

 itself, but from a thin vascular substance resting upon it. 

 This substance, 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 neces- 

 sarily hollow at its growing end, the first part of the growth 

 taking place in the inside of this hollow. Besides this, the 

 plate receives additional layers on the outside, which are 

 formed in the same vascular nidus as it extends along the 

 jaw. This part forms a semi-horny substance between 

 each plate, which is very white, rises with the whalebone, 

 and becomes even with the outer edge of the jaw. This 

 intermediate substance fills up the spaces between the 

 plates as high as the jaw, and acts as abutments to the 

 whalebones, keeping them firm in their places. 



Mr. Hunter further remarks, " that in the growth of the 

 whalebone three parts appear to be formed ; one from the 

 rising cone, which is the centre ; a second on the outside ; 



