26 
CETACEANS. 
Cetaceans by tlie regularity with which it comes to the surface to breathe, although 
there is some variation in this respect according to age. “ When emerging to the 
surface,” writes Captain Scammon, “ the first portion of the animal seen is the 
region of the hump, then it raises its head and respires slowly for the space of 
about three seconds, sending forth diagonally a volume of whitish vapour, like an 
the SPERM-WHALE nat. size). 
escape of steam; this may be seen from the masthead at a distance of three to 
five miles. In respiring at its leisure, the animal sometimes makes no headway 
through the water; at other times it moves quietly along at the rate of two or 
three miles an hour, or, ‘ if making a passage ’ from one feeding-ground to another, 
it may accelerate its velocity. When in progressive motion, hardly an instant is 
required for inspiration; when the animal dips its head a little and momentarily 
disappears, then it rises again to blow as before, each respiration being made with 
