CETACEA. 211 
portion, which is altogether owing to an enormous develop- 
ment of the bones of the face. 
PHYSETER, Lin. 
The Cachalots(1) are Cetacea with a very voluminous head, exces- 
sively enlarged, particularly in front, in whose upper jaw there’ is 
neither whalebone nor tooth, or if any, very small, and not projecting; 
the lower jaw, narrow, elongated, and corresponding to a furrow in 
the upper one, is armed on each side with a range of cylindrical or 
conical teeth, which, when the mouth is closed, enter into corres- 
ponding cavities in the upper jaw. The superior portion of their 
enormous head consists almost entirely of large cavities, separated 
and covered by cartilages, and filled with an oil which becomes 
fixed as it cools, well known in commerce by the name of spermaceti, 
a substance for which they are principally sought; the body not 
having much fat, and consequently- yielding but little oil. These 
cavities, however, are very distinct from the true cranium, which 
is rather small, is placed under their posterior portion, and contains 
-the brain as usual. It appears that canals, filled with this sperma- 
ceti, or adipocire as it is called, are distributed to several parts of 
the body, communicating with the cavities which fill the mass of the 
head; they even ramify through the fat or blubber that is found 
beneath the skin. 
The odorous substance, named ambergris, appears to be a con- 
cretion formed in the intestines of the Cachalot, particularly during 
certain states of disease, and it is said, chiefly in the cecum. 
The species of the Cachalots are far from being well as- 
certained. hat which appears to be the most common, the 
macrocephalus of Shaw and Bonnaterre, (Lacep. X)(2) in lieu 
of a dorsal fin, has a mere callous prominence. There are from 
twenty to twenty-three teeth on each side of the lower jaw, and 
some small conical ones hidden beneath the gum in the upper 
one. Its spiracle is single, and not double as in the greater 
part of the other Cetacea ; neither is it symmetrical, but is di- 
rected towards the left, and terminates on that side, on the front 
of the muzzle, which is truncated.(3) In addition to this, it is 
said that the left eye is much smaller than the other, and that 
eee | ee ee 
(1) Physeter as well as physalus, signifies blower. Cachalot is the name used by 
_ the Biscayans ; from cachau, which in the Cantabrian dialect means footh. . 
(2) It is not the macrocephalus of Linnzus. 
(3) We have verified on two crania this want of symmetry in the spiracle, an- 
nounced by Dudley, by Anderson and by Swediauer, which inclines us to credit 
the inequality of the eyes mentioned by Egede. 
