XII ASYMMETRY OF SKULL 
anything to do with the 
aquatic life is not so clear. 
It also characterises the 
Sirenia, more or less, and 
the Otters; but, on the other 
hand, the terrestrial Bears 
show the same structure as 
do also some Ungulates. It 
must be borne in mind, too, 
that the kidneys of foetal 
Man are lobulated. 
The liver is a compact 
organ not showing such lobu- 
lation as 1s common, but not 
universal, among mammals. 
The bones of Whales have 
a somewhat loose structure, 
and are much impregnated 
with oil. In many features 
the skeleton of Whales is 
highly distinctive of the 
order. 
The brain case is small 
proportionately and rounded. 
The “ face ” is therefore long, 
and in some cases, especially 
among the fossil forms of 
Platanistidae, the rostrum 
is extraordinarily elongated. 
The asymmetry of the 
Whale’s skull is one of its 
most remarkable features ; 
this, however, is_ entirely 
limited to the Toothed 
Whales, and among them 
is more pronounced in some 
forms than in others. Thus 
the Platanistidae and many 
Ziphioids are not nearly so 
asymmetrical as the Dol- 
pelv 
chev 
chev, chevron 
cerv, wnited cervical vertebrae ; 
jug, jugal ; lwnb.trans, lumbar transverse processes ; max, maxilla ; nas, 
acr, Acromion process of scapula ; 
hu, humerus; hy, hyoid ; 
pelv, vestige of pelvis ; per.ot, periotic ; prmax, premaxilla ; rad, 
Skeleton of Porpoise (Phocoena communis). 
cor, coracoid process ; 
183. 
bones ; 
Fia. 
radius ; rb}, first rib; 7b)%, twelfth rib; sc 
(From Parker and Haswell’s Zoology. ) 
orb, orbit ; par, parietal ; 
uln, ulna; zyg, prezygapophysis. 
st, sternum ; 
supra-occipital ; 
S.0ce, 
scapula ; 
