635 
of Edinburgh, Session 1871-72. 
of the mandible to the middle of a line drawn across the posterior 
ends of the rami. 
Entire 
Length. 
Length 
of Sym- 
physis. 
Greatest 
Girth 
Behind. 
Mandible from Isle of Skye, 
190J 
// 
116 
56 
Proportion, .... 
100 
61 
29 
Mandible in Natural History Museum, 
196 
120 
54 
Proportion, .... 
100 
60 
27 
Mandible in Anatomical Museum, 
80 
381 
29 
Proportion, .... 
100 
48 
36 
Width 
Behind. 
Mandible, young skull, Tasmania, 
49 
21 
31 
Proportion, .... 
100 
43 
63 
Mandible, Tasmanian Skeleton, 
Proportion, .... 
174 
102 
72 
100 
59 
41 
Largest Tasmanian Mandible, 
194 
124 
75 
Proportion, .... 
100 
64 
38 
The specimens in the Edinburgh Museums corroborate the con- 
clusions arrived at by Mr Flower, that a gradual increase in the 
length of the symphysis, compared with that of the entire jaw, 
takes place as age advances, and it is obvious also that the girth 
behind diminishes in proportion to the increase in the length of 
the jaw. This increase is without doubt co-ordinated with the 
development and growth of the teeth. 
Although the teeth had been removed by the fishermen, and sold 
to tourists before the mandible of the Skye sperm-whale came into 
my possession, yet the sockets were entire, and twenty-four on each 
side could be counted, so that the animal had attained its complete 
dentition. Seven loose teeth were, however, sent, all of which, with 
one exception, were worn on the surface and sides of the crown. In 
all, the pulp cavity was completely closed at the extremity of the 
fang, and, in several, irregular outgrowths from the surface of the 
fang were present. Two of the teeth, though worn at the crown, 
closely corresponded in general form with the one not so affected, 
and were much more slender and tapering than the remaining 
four, the roots of which were much more bulky. The unworn tooth 
was five inches long, and the greatest circumference of its root 
inches. 
