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Show 692 ON THE ANATOMY OF THE EPOMOPHORI. [J glossus muscle. The small genio-hyo-glossi arise on each side from the anterior margins of the epihyals. From the pharynx, thus closed in by osseous and muscular walls, no sacs extend outwards as in E. franqueti; but near the commencement of the oesophagus, opposite the opening of the larynx, there is the aperture of a single central sacculus, which lies between the middle constrictor of the pharynx and the spine, its neck passing between the fibres of that muscle, which forms a lozenge-shaped sphincter round it. It is difficult to suggest the office of this sac, the cavity of which in E. macrocephalus is not larger than a small bean, and in E. minor would hardly hold a pea. Owing to the presence of the large inflected extremities of the thyrohyals, which nearly meet in the middle line across the commencement of the oesophagus, the inferior constrictors of the pharynx are much shorter, and do not form a pair of long fleshy tendons carried forwards longitudinally between the extremities of the epihyals as in E. franqueti; while the middle constrictors are distinguishable from them, and part of their fibres form a sphincter for the neck of the sacculus above described. The remarkable form of the hyoid bones and great development of the isthmus faucium part of the pharynx, in which (though especially pronounced in the males of certain species) all the species agree, may be understood when we consider the nature of the food of these animals. In the collection of the British Museum are specimens of E. gam-bianus from the banks of the Zambesi, with the note " eating figs " on the label attached to them by the donor Dr. Kirk. That figs constitute the food of E. francpueti, macrocephalus, labiatus, and minor also I have proved by finding remains of these fruits in the alimentary canals of these species. The fig being a hollow receptacle containing numerous small fruits, is not easily detached from the branch for the purpose of mastication ; and its outer rind is evidently too tough to be readily torn through by the feeble teeth of the Epomophori. The easiest method, therefore, of getting at its soft juicy contents is by sucking them out through the aperture at the distal extremity of the fig. Now the whole structure of the mouth and pharynx of these animals is admirably suited for this purpose. The peculiarly voluminous lips are capable of completely encircling the fig, and their adherence to its smooth surface is evidently securely maintained by the soft pads which spring from their upper margins near the angles of the mouth. While thus encircled by the lips, the fruit is probably slowly chewed by the feeble acutely pointed teeth, and pressed upwards against the prominent palate-ridges so as to cause it to give up more freely its juices and soft contents, which are drawn out by suction through the terminal aperture. The construction of the parts above described is specially suited to the action of suction, accomplished probably by the alternate action of the buccal muscles and the lungs. The spacious pharvnx shut off from the nasal apertures by the constrictors of the pharynx' |