848 SKART—SKELETON 
crown, tail and wings—the last conspicuously barred with white, 
while neither hens nor young exhibit any striations. On the other 
hand, neither sex of the latter at any age puts off its striped garb— 
the mark, it may be pretty safely asserted, of an inferior stage of 
development. ‘The remaining species of the group, mostly South- 
American, do not seem here to need particular notice. 
SKART, see ScarF and Scart (p. 815). 
SKEEL-DUCK, SKEEL-GOOSE, SKEELING and SKELDER 
(see SHELDER), local names for the SHELD-DRAKE, the last also 
applied to the OYSTER-CATCHER, 
SKELETON, the bony framework of a Bird or other vertebrate 
animal which, from the ease with which it can be freed from the 
more perishable soft parts of the body and durably preserved, has 
long attained a pre-eminent place in anatomical study. This pre- 
eminence is still further justified not only from the numerosity of 
the bones composing the skeleton—the very number alone affording 
great amplitude of differential variability—but because each indi- 
vidual bone is modelled by its neighbouring soft parts, and notably 
by the muscles, so that its shape reflects (so to speak) important 
features of the various organic systems (page 604). Most bones, 
either in their shape generally, or from the processes, tuberosities, 
crests or foramina they exhibit, are so characteristic that it is 
frequently possible to determine not only the Family but even the 
genus or species of Bird to which they belong. Unfortunately it 
often happens that the characters selected for taxonomic purposes 
are those which are the easiest to describe rather than those which 
are the most important. For convenience of treatment the Skeleton 
may be regarded as made up of three chief portions—the Head, the 
Trunk and the Limbs. Frequently a distinction is made between 
the Axial and the Appendicular Skeleton— the former being 
restricted to the Vertebral Column and the Cranium proper, while 
the latter comprises the Riss, Breastbone (STERNUM), Limbs and 
their arches, the Hyo1p apparatus and the Jaws. 
THE VERTEBRAL CoLUMN has for its chief function the support 
of the Head and Limbs, as well as the protection of the Spinal 
Cord, the Vertebras being its constituent units. These last are 
distinguished, according to the several regions of the trunk, as 
Cervical, Dorsal, Sacral or Pelvic, and Caudal, and may be defined 
as follows :— 
I. Cervical Vertebre are all those that lie between the SKULL 
and the first vertebra which is connected with the sternum by a 
pair of complete ribs; but they may be subdivided into 
(a) Cervical Vertebre, in the strict sense — either without 
rudimentary ribs, as the Atlas, or having rudimentary ribs which 
are fused with the vertebra ; and 
