OCR Text |
Show 844 MR. P. E. BEDDARD ON THE [Dec. 3, moreover, ends on the fibrous aponeurosis already spoken of as lying behind the lung. (3) A s in Rana and Pipa, the sterno-hyoid muscle bifurcates below the sternum into an anterior and posterior section. In Xenopus the posterior branch is a rather thin and narrow muscle which passes down at the level of the anterior end of the heart Fig. 3. Thigh-muscles of Xenopus. Sa., sartorius; St., semitendinosus ; B.i.mag., rectus internus major ; R.i.min., rectus internus minor. at right angles to the sternum. The muscle is attached to the outer side of the wall of the sac which encloses the heart and pericardium, and is therefore posterior to all the great vessels which enter and leave the heart. Its fibres, which do not fan out to |