File:Bulletin - United States National Museum (1918) (14784679702).jpg

Identifier: bulletinunitedst9911918unit (find matches)
Title: Bulletin - United States National Museum
Year: 1877 (1870s)
Authors: United States National Museum Smithsonian Institution United States. Dept. of the Interior
Subjects: Science
Publisher: Washington : Smithsonian Institution Press, (etc.) for sale by the Supt. of Docs., U.S. Govt Print. Off.
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Smithsonian Libraries

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of other zoo-reared lions as well, are the greater (relative andactual) zygomatic breadth, the large rostra, and the great distanceacross the base of the skull at the mastoids. While actually measur-ing less in condylobasal or greatest length than many of the wildmassaica skulls of equal age, they have a far greater zygomaticbreadth than any, averaging about 30 millimeters more in males, and20 mUhmeters more in females. (See detailed measurements, pages166-167, and plates 52-54.) The difterent regions of tlie skull maybe compared in detail: Regions oi attachment of the masseter mwsfZ^.—Contrary to the usualtextbook definition of its function, the masseter muscle unquestion-ably furnishes the chief gripping power; it is the one most exercisedduring use of the canine and incisor teeth. ^Vliile there is intimaterelationship between the functions of the masseter and temporalmuscles, and the two masses are actually connected, each nevertheless EAST AFRICAN MAMMALS IN NATIONAL MUSEUM. 159
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is the prime factor in the delinitc mechanical action of separate partsof the dental row. While the masseter, as stated above, has primarilyto do with the front teeth (the canines and incisors), the temporalis chiefly concerned with the molar-premolar row, and the process ofcuttin<j; and chewing rather than biting and gripping. The lion, hkeall cats, is a biting animal of the highest type. The masseter, aidedby the temporal and internal pterygoid muscles, locks the jaw andmakes the grip firm. It is attached to ahnost the entire length ofthe inner side of the zygoma, from just back of the molar tooth to thepit on the upper side of the squamosal root, and to the ventral half ofthe outer surface from near the maxillary tuberosity to near theglenoid surface. The region of its origin in the McMillan skulls isgreatly changed from the wild type. The malar and the zygomaticprocess of the temporal bone havebeen almost uninfluenced by themuscle and have to a certain de-gree retained distinct

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