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The Notes on the Temporal bone in Mammalia. 

 (Chiefly in Primates). 



By Prof. Richard J. Anderson (Galway, Irland). 



The temporal bone is often regarded as a bone of the face 

 even more than a bone of the Cranium. This holds perhaps more 

 with regard to the squamosal, which supports the mandible and 

 the maxilla to some extent in their functions. The squamous 

 reinforces the parietal to such an extent that much of the inner 

 surface is separated from the Cranial cavity by the latter bone. 

 It is evident that in many animals the squamous is of short ver- 

 tical measurement, so that it is of less apparent importance as a 

 cranial than as a facial bone. The parietal rather than the tem- 

 poral in mammals seems to emphasize the cerebral development. 

 In the Equidae, Vespertilionidae, Myoxidae, an independance of 

 mechanical function in limited, as far as the tympanic in the 

 latter and the squamous in the former is concerned. Le Double 

 mentions that a figure (Mar che) of a young Gorilla, in the col- 

 lections du Museum d'histoire naturelle de Paris, shows a portion 

 of the squamopetrous soture which is open in the young Chim- 

 panzee. In man the squamous is rarely met with as a separate 

 bone. The zygomatic part and the scale-like part have been 

 seen separate. This arrangement is due probably to develop- 

 mental causes. M e c k e 1 and Gruber, M. Le Double 

 mentions, found the „temporal" part divided, this I believe I have 

 seen once. The upper portion may be Wormian. It seems (in man) 

 to be developed from three osseous points (upper part of scale, 

 (2) Zygoma and Ear part). The Tympanic has also three ossi- 

 cular foci (middle, anterior and posterior) . The views of A 1 - 

 bricht with reference to the squamous part of the temporal 

 are.not accepted. It is perhaps impossible to find an exact homo- 

 logue, as it is often impossible to find the exact number of osseous 

 foci, this is owing to the readiness with which bone is absorbed 

 and deposited, and the ease with which a bone totally different 

 in form and connections assumes the position of an earlier deposit. 

 Four foci may be present for the squamous. This condition is 

 very rare in Primates. M. Le Double furnishes as with a 

 list of sutures in the Squamosal of Primates. A double is given 



