186 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.53. 



Regions of attachment of the temporal muscle. — The temporal 

 muscles, chiefly concerned with the cheek teeth rather than with the 

 front teeth,^ have had less influence in changing the type of skull of 

 the captive lion, than have the masseters. The lion in captivity has, 

 as a matter of fact, used his temporal muscles in much the normal 

 way of a wild lion, whereas the natural function of the masseter is 

 almost entirely discontinued in a captive animal which does not kill 

 its own prey. As a precaution against the natural tendency of the 

 animals to bolt their food without mastication, the lions in the 

 Zoological Park are regularly fed pieces of meat with large bones. 



The region of origin, the entire side of the skull posteriorly, is 

 somewhat modified. The brain case has been less subjected to pressure 

 by these powerful muscles than in the wild lion; the muscles have had 

 less to do W'ith moulding its shape during the process of absorption 

 and ossification ; and it, as a consequence, is less compressed laterally. 

 Wild lion skulls of equal age have smaller braincases, more sharply 

 marked sagittal and lambdoidal crests. The region of insertion, the 

 inner surface of the ascending ramus, is slightly smoother in the 

 McMillan lions, but is little modified. 



Capacity of the hrahicase. — As stated above, external measure- 

 ments of the braincase in wild lions are less than in park-reared 

 animals of equal age. The capacity of the braincase, however, is 

 considerably greater. Young adults of each, as usual among carni- 

 vores, have greater braincase capacity than old or aged adults. The 

 bones forming the cranium of the Zoo lion are thicker, and the 

 actual size of the brain is less than in w^ild-killed examples. In the 

 case of the McMillan lions the capacity is about 50 cubic centimeters 

 less in males and about 40 less in females, than in wild-killed ex- 

 amples of equal age from the same locality. 



The "Richardson lion," from the New York Zoological Park, cele- 

 brated as the record skull for greatest breadth,^ and the Menelik lion, 

 the type-specimen of Felis leo roosevelti, are both park-reared ani- 

 mals of uncertain history but they show the skull characters of cap- 

 tive lions to a marked degree. Even the skulls of these enormous 

 lions, although the animals represent forms unquestionably larger in 

 a wild state than Felis leo nmssaica, have less braincase capacity than 

 any wild-killed examples of the East African lion. 



1 A fox skull, in the Vienna Museum, with a defective left lower carnassial tooth, 

 exhibits an asymmetrical condition because the animal used its right temporal muscle 

 to such a degree as to develop this muscle far above the nornial strength, while the 

 left temporal muscle was very weak from little use. The right temporal ridge on the 

 skull was pushed up almost to the sagittal line while the left temporal ridge remained 

 below its normal elevation for that age. The occipital crest is likewise asymmetrical. 

 (Toldt, Zool. Anz., vol. 39, pp. 17G-191, figs. 1-4. July 4, 1905.) 



2 See Koosevelt and Heller, Life-Histories of African Game Animals, vol. 1, 1914, 

 p. 225. 



