GENERAL CHARACTERS. 5 
wide open, the upper part of the windpipe (larynx) is prolonged so as to reach the 
opening of the nostrils in the hinder portion of the mouth, and thus form a closed 
tube from the external nostrils to the lungs. 
As there is frequently some misconception as to the so-called 
“spouting” or “ blowing” of Cetaceans, a few words are advisable on 
this point. When a whale comes to the surface of the water after a longer or 
shorter period of submergence, its first act is to discharge the air from the lungs 
previous to taking a fresh inspiration. The air is expelled from the lungs with 
great force, and thus rises a considerable height above the surface of the water, 
and as it is saturated with water-vapour at a high temperature the contact with 
the cold external air at once condenses this vapour, which forms a column of steam 
or spray. Frequently, however, a whale commences to “blow” before its nostrils 
are actually above the surface, and then a certain amount of sea-water is forced up 
with the column of air. 
Cetaceans include the largest animals now existing on the globe; 
: and they were only approached in point of size by some of the 
gigantic land reptiles which existed during the Secondary period. As a group, they 
are comparatively modern, being unknown before the upper portion of the Eocene 
division of the Tertiary period. In the preceding Secondary period their place in 
the ocean was taken by huge extinct marine reptiles, such as the ichthyosaurs and 
plesiosaurs ; but as these seem to have died out at the close of that period, while 
whales are unknown in the early part of the Eocene, it would seem that there 
was an interregnum, during which our seas were not tenanted by any large 
animals except fishes. 
Difficulty of From their oceanic habits and huge size, the study of the larger 
Observing. Cetaceans is a matter of extreme difficulty; the majority of the 
comparatively few specimens that are cast ashore not being seen by naturalists, 
while even in cases where opportunity is afforded for inspection, the bodies are 
usually more or less distorted from their proper form, while nothing can, of course, 
be learnt as to the habits of the animals. The acquisition of such knowledge as 
we possess of the habits and form of the larger whales has consequently been 
acquired very slowly; but, thanks to the careful observations of several gentlemen 
engaged in the whaling trade, we have a considerable amount of information on 
these subjects, although there is room for much further investigation. 
Cetaceans are found in all seas, from the Equator to within the 
Arctic Circle; and in former years even many of the larger species 
were extraordinarily abundant in certain regions, although they have been greatly 
reduced in numbers, and in some instances almost or completely exterminated. 
Many of the smaller forms, known as porpoises and dolphins, ascend rivers for 
longer or shorter distances; while some of these, as well as all the members of one 
family are exclusively fluviatile; the latter inhabiting the larger rivers of South 
America and South-Eastern Asia. With the single exception of a kind of dolphin 
recently discovered in the large rivers of the Cameruns district on the West Coast 
of Africa, which is believed to be herbivorous, all Cetaceans are carnivorous. Their 
food is, however, very varied; and the size of the animals devoured for food bears 
no sort of relation to the dimensions of their devourers. Thus while the killer, or 
Spouting. 
A Modern Group. 
Distribution. 
