1 8 THE COMMON COLICS OF THE HORSE 



left sac, which it completely covers, leaving the right sac 

 (indicated by the dotted lines) uncovered. In the lesser 

 curvature its fibres become somewhat abruptly lost, while 

 the greater curvature retains them to the entire envelop- 

 ment of the underneath surface of the right sac, on 

 whose upper surface they become gradually obliterated. 



Fig. 5. —Middle Muscular Coat of Stomach. 



a, Circular fibres (in one position lined more blackly than their 

 neighbours). There is no aggregation of these fibres.^ 

 A, (Esophagus ; B, left sac ; C, right sac ; D, duodenal S-trap. 



2. A Middle Plane. — The fibres of this are again 

 a continuation of the muscular coverings of the oesophagus 

 — viz., of its circular coat (see Fig. 5). Running beneath 

 the fibres of the superficial plane, the middle coat also 

 envelops the whole of the left sac. Where the fibres of 

 the superficial plane become indistinct in the position of 



1 This darker lining is for purposes of emphasis only. — H. C. R. 



