100 ALES' HRDLIKA 



festations of senile resorption are of little value as indices of the age of 

 the individual in years. 1 



Identification of Parts. Given a series of crania, and perhaps other 

 bones, for examination, we frequently find that some of the lower jaws 

 have become detached from the skulls, and various bones separated 

 from the skeletons to which they belong. We may further find 

 individual crania, or even larger admixture, of a different type from 

 that of the rest of the collection. Our object naturally will be to 

 properly fit the stray parts, and segregate the heterogeneous specimens. 

 This once more demands considerable care and experience. 



The fitting of the lower jaw to its skull is fairly easy if we have to 

 deal with only a few specimens; but in larger collections, and even in 

 some individual cases where more or less warping of the lower jaw has 

 taken place, the task may be quite difficult. The main guidance of the 

 student will be the fit of the teeth, the fit of the condyles, the color and 

 mottling of the specimens, and various conditions and peculiarities 

 of the teeth. He will find a similar or compensatory wear of the teeth 

 in the two jaws of the same individual; a correspondence of more or 

 less extruded or unworn teeth (especially the third molar) in one jaw, 

 to absence of opposite tooth in the other; a similar staining of or con- 

 cretions about the teeth; etc. But there may be anomalies in one 

 (especially the upper) jaw for the counterparts of which he would 

 vainly look in the other. 



As to other parts of the skeleton, which may be touched upon in this 

 place, we can only hope to establish whether or not a certain bone 



1 Consult: Allen (Harrison), "On the effects of disease and senility as illustrated 

 in the bones and teeth of mammals," Science, 1897, V, 289-294. 



Brousse" (A.), "De 1'involution senile," 8, Paris, 1886. 



F<re" (C. H.), "Sur 1'atrophie senile symmetrique des parietaux," Bull. Soc. 

 d'Anthrop., Paris, 1876, S. 2, XI, 423. (cont'd next p.) 



Humphry (C. M.), "Senile hypertrophy and senile atrophy of the skull," J. 

 Anat. and PhysioL, London, 1890, XXIV, 598. 



Le Courtois, "Modifications morphologiques de la voute cr&nienne osseuse 

 suivant 1'age et le type cranien," Bvtt. Soc. d'Anthrop., Paris, 1870, S. 2, V, 607-620. 



Pozzi (Senile changes in the skull). Diet. Encycl. d. Sc. Med., XXII, 492. 



Sauvage (H.), "Note sur !'<tat senile du crane," Butt. Soc. d'Anthrop., Paris, 

 1870, S. 2, V, 576. Also sep., Paris, 1870, 132 pp. 



Smith (G. Elliot), "The causation of the symmetrical thinning of parietal bones 

 in ancient Egyptians," J. Anat. and PhysioL, London, 1907, XLI, 232. 



Thomas (O.), "Notes on a striking instance of cranial variation due to age," 

 Proc. Sci. Meetings Zool. Soc., London, 1886, P. I, 125 pp. 



Virchow (R.), "Ueber die Involutionskrankheit (Malum senile) der platten 

 Knochen, namentlich dee Schadels," Ges. Abh., 1856. 



