~ The Mermaid of Early Writers. — 163 
apertures Which have been named spiracles, placed on the summit 
of the head, in a perpendicular direction, by which are performed 
the functions of respiration, and of the ejection of the water which 
passes into the mouth during the act of feeding. — As an article of 
commerce, every one is acquainted with that peculiar production 
which supplies the place of teeth in the whale; but it does not 
elaim consideration amongst these generalities. 
The enormous size of the cetacea is perhaps one of the most 
amazing facts in their history. Varying in developement from the 
most colossal proportions to the ordinary size of other beings, they 
are in their extreme bulk the largest of known animals. Indeed it 
1s natural, says Lesson,* that these giants of the animal kingdom, 
occupying the immense deserts of the sea, should bear relation to 
the vast surface which they have to animate. Thus the extensive 
wastes of Africa are the habitations of the largest quadrupeds, such 
as the African elephant, the rhinoceros, the giraffe, &c. And thus 
the uplands of Asia nourish the Asiatic elephant and the tiger ; and 
in Borneo live the great orangs. 
The habits of the cetacea vary in the different groupes. The 
whales are stupid and unwieldy, but move with great power ; the 
eachalots are fierce and courageous ; the dolphins warlike and vo- 
racious. The developement of the brain bears an interesting rela- 
tion to the manners of the animal; of little magnitude in any of 
the cetacea, in proportion to the bulk of the body, it assumes its 
maximum in the dolphins, and their possession of superior intelli- 
gence is by all attested. 
The period is but little distant to which we can look back with 
any degree of complacency on the nature and amount of our know- 
ledge of these animals. Associated with the fishes anteriorly to 
the time of Bloch, they continued for many years the objects of 
vague though frequent descriptions ; their history was but imper- 
fectly related even in the classical works of Bonnaterret and Lace- 
pede; and we hasten to the “ Regne Animal” for the true arrange- 
ment of the cetacea, and to the labours of Lesson|| for an encyclo- 
pedia of the facts known in their natural history. 
The order of cetacea was first divided by Cuvier into two fami- 
lies, the herbivorous cetacea, (Sirenia,) and the cetacea proper, 
which last are piscivorous. As the dugong, towards whose history 
these preliminary remarks are directed, forms one of the genera 
which compose the first division, we shall now confine ourselves 
exclusively to that branch. 
The whole of the cetacea are formed on a type of great similari- 
ty: the striking differences observed amongst other orders of ani- 
mals, are in vain sought for amongst them. The law of variety is 
principally developed in the dental system ; thus the sirenia are 
distinguished from the common cetacea by the flat crowns of their 
* Complément 4 Buffon, tom. 1. + Cétologie, 4to. 1789. 
{ Hist, Nat. des Cétacés, 1804, “|| Loc. Cit. 
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