CHAPTER IV. 
BREATHING. 
All the cetacea, as is well known, are warm-blooded 
animals, and possess lungs, and a corresponding respi- 
ratory apparatus resembling those of terrestrial animals, 
and require consequently a frequent intercourse with 
atmospheric air, and for this purpose it is of course 
necessary that they should rise to the surface of the 
water at certain intervals. 
The majority of this class of animals do not appear 
to perform this function with any regularity, and it is 
in this respect that the sperm whale is remarkably 
distinguished among his congeners, and it is from his 
peculiar mode of “blowing” that he is recognised even 
from a great distance by the most inexperienced whaler. 
When at the surface for the purpose of respiration, the 
whale generally remains still, but occasionally continues 
making a gentle progress during the whole of his 
breathing time. If the water is moderately smooth, the 
first part of the whale observable is a dark-coloured 
pyramidal mass, projecting about two or three feet out 
of the water, which is the “ hump.” 
At very regular intervals of time, the nose, or snout, 
emerges at a distance of from forty to fifty feet from the 
hump, in the full-grown male. From the extremity of 
