136 REPORTS ON THE STATE OF SCIENCE.—1914. 
(f) Dorsal Fin.—The dorsal fin of the Sperm Whale consists of 
a prominent elevation, which rises to a height of from 14 to 18 in. 
above the line of the back. The fin is succeeded by a series of about 
six much smaller prominences which decrease in size towards the 
tail. None of these at all approaches the altitude of the dorsal fin. 
They are, nevertheless, quite obvious. On the ventral surface the 
keel of the caudal region is continued forwards towards the anus as 
a much more definite ridge than in the Balenopterids. 
(g) Flipper.—The shape of the flipper is somewhat variable. In 
No. 21 the left pectoral appeared to have been damaged at some 
period, as there was a large notch on the preaxial side of the tip. 
(h) Spermaceti.—In every specimen the quantity of this substance 
was large, usually constituting about one-third of the total oil yield 
of a whale of this species. It occurs all over the body as well as in 
the head, but no attention is paid to it except in the head, the rest 
merely contributing to the general production of ‘sperm oil.’ In 
the head there are three extensive cavities, an anterior single cavity 
and two lateral cavities. They all occur in the interior of a huge 
mass of exceedingly dense, fibrous connective tissue, which, when 
drained of spermaceti, is of a snowy whiteness. This mass con- 
stitutes the great bulk of the head, and rests upon the large cup- 
like structure formed by the bones of the rostrum. The cavities 
do not appear to possess definite linings, and when the oil runs out, 
masses of light, spongy tissue filled with the liquid fat run out also, 
as if they had been loosely attached to the walls of the cavity. They 
are probably liberated by the instruments introduced through the wall 
of the cavity in the process of tapping the spermaceti. 
The following is the method of tapping. After the whale is flensed, 
the body is cut off from the head, which is left lying on its side. 
The whole head is covered by a thick coat of mixed muscle and 
tendon running longitudinally. The tendons are conspicuous, and 
may be removed in considerable lengths with little difficulty. The 
cutting of the hole in this capsule is an arduous work, and may 
occupy nearly an hour. A mid-dorsal and an anterior aperture are 
made, and when the cavities have been penetrated, the spermaceti 
runs out as if from a pipe. A movable wooden gutter is placed beneath 
the hole, by means of which the oil is run into the two open boilers, 
in which it is cooked. 
Spermaceti is an almost colourless, transparent liquid, having a 
pale yellow tinge. It has not any noticeable odour, and the flavour 
is very faintly fishy, resembling that of a fresh duck ege. After 
boiling, the oil has a dark yellow colour while liquid. When cold, 
both before and after boiling, it sets stiff, but is not hard, the con- 
sistency being about that of lard. The uses of this oil have been 
indicated in the Introduction. 
From the position of the spermaceti, and also of the blow-hole in 
Physeter, the following function of the former may be suggested: The 
food of the Sperm Whale is, in the main, composed of cuttlefish 
such as Architeuthis. As these forms are bathypelagic, it follows 
that the whales must descend to considerable depths to feed, and 
