OCR Text |
Show 318 DR. H. GADOW ON THE SPECIES OF RHEA. [M thin spindle-shaped semitendinous head from the pubic spine. This additional little slip is probably the last trace of the ambiens muscle, whch is now generally lost by the Passerine birds. The case above described is one way in which this muscle gets lost ; in other cases, e.g. Ciconia and Phoenicopterus, the reduction does not begin by its tendon becoming attached to neighbouring tendons in the knee-region, but the whole muscle shows a diminution of its tendon and belly to a mere thread, till at last this also disappears, e. g. in Abdimia and Xenorhynchus. Digestive Organs. The digestive organs of Rhea darwini did not present any remarkable differences from those of Rh. americana, and a comparison of the relative dimensions was not advisable because of the different age of the specimens examined. The hepatic and pancreatic ducts, together with the shape of the Fig. 7. Rh. americana. The duodenal loop and pancreas, with the first and second pancreatic ducts (pL aud p.2), and showing the hepato-enteric duct (he), the cystico-enteric (ce), and the hepato-cystico-enteric duct (Ace). Fig. 8. Rh. darwini, $. The duodenal loop is represented too wide in this figure. pancreas of Rhea darwini 3, showed an arrangement somewhat different from that of the Rhea americana described by myself in the ' Jenaische Zeitschrift.' See figures 7 & 8. Respiratory Organs. There are some differences in the shape of the posterior margin of the upper larynx, as will be seen in the following wooducts : |