at 
CETACEA—LILLIE. 105 
external surface of the tympanic membrane and the plug of ear-wax, exactly as they 
oceur in Balaenoptera. 
Mr. Burfield and Mr. Erik Hamilton noticed that in several of the Balaenoptera 
examined by them off the Irish coast, the meatus was closed up for a part of its course, 
as described here in the case of the Humpback. 
I overlooked this closed area when working at the ear in Balaenoptera musculus 
Linn. and B. physalus Linn. a few years ago.* The presence of water in the imner 
portion of the meatus of one or two of these specimens led me to think that the 
meatus was open to the exterior throughout its whole length, and was normally full of 
sea-water. Iam now inclined to believe, however, that the occurrence of the water in 
the meatus was accidental, and due to the whalers playing the hose over my dissections 
when washing the “ flensing slip” during my absence. Sea-water hoses were kept 
constantly running when whales were being cut up on the “slip.” 
Carte and Macalister reported the meatus as open in Balaenoptera acutorostrata, 
Lacépéde, and it may be so in that species; but unless the canal is very carefully 
sectioned throughout its entire length it is easy to overlook the few inches which are 
closed up. 
In Balaena mysticetus the meatus has been figured by Gray,f and was recorded 
by him as open, though of a very small diameter in its outer part. The investigation, 
however, does not appear to have been sufficiently close to preclude the possibility of 
his having overlooked the closed area. 
The plug of ear-wax which occurs in the meatus of the Humpback has been 
recently figured and described by Sir William Turner.§ — It is therefore only necessary 
to say that plugs similar to the one described by him were found in all the adult 
specimens; but the plug had not begun to form in the embryo of 134 feet in length. 
With reference to Turner’s suggestion that the length of the plug may bear a 
relationship to the thickness of the external coating of blubber over the head, I would 
here point out that the plug only occurred in the wide portion of the meatus, close to 
the tympanic membrane, and was therefore more than a foot away from the coat of 
blubber, in a Humpback of average size. Moreover, the diameter of that portion of 
the meatus which traverses the blubber is only 7/5 inch, whereas the width of the plug 
is seldom less than $ inch in its narrowest part. 
The tympanic membrane had the same shape as in Balaenoptera. In an adult 
whale, the total length of the sac and ligament was 34 inches, and the greatest 
diameter was 1 inch. 
The walls of the meatus were compressed and closely surrounded the plug of wax, 
imprinting upon it the impressions of the ridges and furrows of their inner surfaces. 
* Lillie, D. G., Proc. Zool. Soc., 1910, p. 775. 
} Carte and Macalister, Phil. Trans., 1867, p. 252. 
t Gray, R., Journ. Anat. and. Physiol., Vol. XXIIT., 1889, p. 300. 
§ Turner, Sir W., Proc. Roy. Soc. Edinb., 1913, Vol. XXXIV., Pt. 1 (No. 2), p. 11. 
