| OCR Text |
Show 1895.] ANATOMY OP PIPA AMERICANA. 831 muscle arises from the thigh close to the rectus femoris*. runs forward, increasing in breadth and undergoing a corresponding diminution in thickness ; ultimately it fans out over the back of the lung and of the oesophagus ; it begins to be attached to the lung first at the origin of the smaller lobe of that viscus. I cannot but think that the close attachment of the muscle to the lung must have some relation to the function of respiration. The main mass of the muscles, however, go past the lung, and are, as already stated, inserted upon the oesophagus. At their insertion, which is on the median ventral side, they not only fan out, but the muscle becomes separated into a number of small separate bundles. The corresponding muscle of the opposite side of the body has to perforate the mesentery on its way to be inserted on to the oesophagus. All the fibres of the muscle are not, however, inserted in this way on to the oesophagus; a good number of them fan out Fig. 2. st.h. o.d. m Pipa surinamensis. Dissection to display diaphragm. o.d., oviduct; a, branch of obliquus muscle; st.h., sternohyoid. Other letters as in fig. 1. dorsally and are inserted on to the aponeurosis already spoken which shuts off the abdominal cavity in front. The arrangement of these fibres is shown in the accompanying drawing (fig. 2). 1 See p. 839. 53* |
