12 
Proceedings of the Royal Society of Edinburgh. [Sess. 
end. The specimen was not labelled, but had probably been from the 
meatus of another Megaptera. 
Balcenoptera sibbaldi . — A single plug of earwax from one meatus of a 
Blue Whale, captured in South Shetland in 1912, was sent. It had been 
injured at the tympanic end, and only a portion of the cup-like cavity had 
been preserved. The plug was 50 cm. (nearly 20 inches) long, 26 mm. 
(1 inch) broad, and 12 mm. thick at its deep end. It gradually diminished 
in breadth and thickness, so that the opposite outer end, though 20 mm. 
(| inch) broad, was only 3 mm. thick, and possessed a flattened, ribbon-like 
aspect (fig 2, A). The surfaces of the plug were fluted longitudinally, and 
Fig. 2. — Earwax from meatus of Balcenoptera sibbaldi , natural size. A, outer fourth of plug with 
thin flattened end to the right ; B, tympanic end with cup -like depression. 
had doubtless been adapted to ridges and furrows on the surface of the lining 
membrane of the meatus. Cough tre} T had noted that the plug gave a very 
good impression of the canal in which it was situated. The tympanic end 
of a second plug, 80 mm. long, 34 mm. in greatest breadth, and 15 mm. 
thick, had been preserved. The cup-like cavity was nearly complete and 
was 15 mm. in depth (fig. 2, B). 
The length of the auditory meatus in the Cetacea bears a proportion to 
the thickness of the blubber on the side of the head. If the wax plug 
were in every case of equal length with the meatus, it would be a gauge to 
the thickness of the blubber, but in the specimen dissected by Lillie the 
plug was not equal in length to the meatus. I am not acquainted with 
any exact measurement of the thickness of the blubber on the side of the 
head in Megaptera. Sir John Struthers in his account of the Tay 
