104 «TERRA NOVA” EXPEDITION. 
The position of the small, slit-like earhole on the surface of the head of this whale 
has been noted by Struthers.* 
From this orifice a narrow tube, about 5'5 inch in diameter, traversed the blubber, 
which was about 34 inches thick in this region of the head. The tube was continued 
through the underlying tissue for about 2 inches, and gradually decreased in diameter 
until it ended blindly. 
The meatus was here closed up for 3 inches of its course. (See text-fig. 10, N.) 
It then widened out again, somewhat abruptly, to a diameter of rather more than 
Fic. 10.—Diagram of the outer and middle ear of a Humpback (Meyaptera). 
A, passage of nares leading to blowhole ; B, opening of pterygoid fossa tube 
into nasopharynx ; C, opening of Eustachian tube into nasopharynx ; D, velum 
palati; E, epiglottis tube; F, pharynx leading to mouth; G, opening of air- 
passage into pterygoid fossa; H, opening of Eustachian tube into tympanic 
cavity ; 1, tympanic bulla ; J, coat of yellow elastic tissue and fat ; K, spong 
layer containing air; L, tympanic membrane; M, wide inner portion of 
external auditory meatus containing plug of ear-wax; N, portion of meatus 
closed up ; O, narrow portion of meatus opening on surface of head. 
an inch, and maintained a fairly uniform size for the remainder of its passage to 
the tympanic bulla. 
The total length of the canal was about 1 foot 9 inches in a Humpback whale 
40 feet in length. 
The walls of the wide innermost portion of the meatus (text-fig. 10, M) were 
invariably pressed together. The sole contents of this tube consisted of the finger-like 
* Struthers, J., Journ. Anat. and Physiol., 1888, Vol. XXIL., p. 122. 
