Structure and Occononty of Whales. 40 1 
lutes hair, nails, claws, feathers, &c. it is wholly compofed 
T)f animal fubftance, and extremely elafiic *. 
Whalebone confifis of thin plates of fome breadth, and in fome 
of very conhderable length, their breadth and length in fome de- 
gree correfponding to one another; and when longeft they are 
commonly the broadefr, but not always fo. (See Tab. XXII.) 
Thefe plates are very different in lize in different parts of the fame 
mouth, more efpecially in the large Whalebone Whale, whofe 
upper jaw does not pals parallel upou the under, but makes an 
arch, the femidiameter of which is about one-fburth of the 
length of the jaw. The head in my poflefiion is nineteen feet 
long, the femidiameter not quite five feet : if this proportion 
is preferred, thofe Whales^ which have whalebone fifteen feet 
long muff be of an immenfe fize. 
Thefe plates are placed in feveral rows, encompafling the 
outer fkirts of the upper jaw, fimilar to teeth in other animals. 
They hand parallel to each other, having one edge towards 
the circumference of the mouth, the other towards the center 
or cavity. They are placed near together in the Piked Whale, 
not being a quarter of an inch afunder where at the greateff 
diffance, yet differing in this refpedt in different parts of the 
fame mouth ; but in the great Whale the difiances are more 
confiderable. 
The outer row is compofed of the lohgeft plates ; and thefe 
are in proportion to the different diftances between the two 
jaws, fome being fourteen or fifteen feet long* and twelve or 
fifteen inches broad ; but towards the anterior and pofierior 
part of the mouth, they are very fhort : they rife for half a 
foot or more, nearly of equal breadths, and afterwards Ihelve 
off from their inner fide until they come near to a point at the 
* From this it muft appear, that *the term bone is an improper one. 
L 1 1 2 outer: 
