82 PECULIARITIES OF THE SPERM WHALE. 
vera, or true skin, infiltrated with oil, or fatty matters. Its 
thickness on the breast of a large whale is about fourteen 
inches, and on most other parts of the body it measures 
from eight to eleven inches. The head is not, however, 
supplied with this covering, having only the black skin, 
or cutis, which lies close to a layer of very dense cellu- 
lar tissue, under which is seen a considerable thickness 
of numerous small tendons, intermixed with muscular 
fibres. 
This is more especially observed on the top and upper 
third of the head, surrounding the case, as lower down 
we find the black skin lying close to the peculiar struc- 
ture of the junk* 
This thick covering of skin, blubber, or fat, is called 
by South Sea whalers the “blanket.^ It is of a light 
yellowish colour, and, when melted down, furnishes the 
sperm oil. It also serves two excellent purposes to the 
whale, in rendering it buoyant, and in furnishing it with 
a warm protection from the coldness of the surrounding 
element ; in this last respect answering well to the 
name bestowed upon it by the sailors 3 
