I. The Sublumbar Muscles

The psoas minor begins at the disc between the twelfth and thirteenth thoracic vertebræ.

The psoas major has a fleshy origin on the posterior border of the last rib, and a thin tendon attached to the twelfth rib.

The iliacus begins under the body of the sixth lumbar vertebra, and is more closely united with the psoas major than in the horse.

The quadratus lumborum extends as far forward as the body of the tenth or eleventh thoracic vertebra.