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THE STRUCTURE OF THE HORSE 



for the purposes of locomotion, and which are attached 

 to the trunk by the intervention of solid structures, 

 commonly called in anatomical language 'girdles.' 

 These are so called because the pair of them, when com- 

 pletely developed, nearly encircle the body ; but it must 

 be admitted that it is not a very happy expression, as, 

 except through the intervention of the vertebral column, 

 they never form complete circles, and very often the 

 ' semigirdles ' of each side are widely separated both 

 above and below. 1 



These girdles and the limbs which they support are 

 never more than two in number on each side, and are 

 almost always placed, the one near the front, and the 

 other near the hinder, end of the trunk. 2 The anterior 

 girdle and limb are often called 6 pectoral/ and the pos- 

 terior 4 pelvic,' from the regions of the body in which 

 they are situated. Though in the large majority of 

 vertebrated animals both pairs of limbs are present, 

 either one or the other may be in a very rudimentary 

 condition, or even altogether wanting, though in such 

 cases some trace of a girdle is nearly always found. 



1 The semigirdles are sometimes called ' arches,' which is hardly 

 more expressive, as, though the word means a segment of a circle 

 in any position, the transverse position is now almost universally 

 associated with it. 



2 In some fishes the ventral fin, which corresponds to the hind 

 limb of rqost vertebrates, is placed below, or even anterior to the 

 pectoral fin, or true front limb. 



