Appendix C. 



DETKKMINATION OK Tilt; A(iK OK SKKLLS. 

 [ AbrUlj^i-'d from Broca'u luHtructiuiiu*.) 



TIrtc iuc to be (listinjiuished the following periods: First period of childhood, second period 

 of chihlliood, adult a^e, ripe ago, seuility. These indications are enoii;;li and are worth more 

 than those of years of age because the anatomical and physiological phenomena which they dem- 

 onstrate are moie or less precocious according to individuals or according to race, lu our race 

 these periods corresjiond nearly to the following ages: 



First i)eriod of chihihood, from birth to the end of the sixth year: 



Second period of chihihood 7 to 14 years. 



Youth 14 to l-'5 years. 



Adult age 25 to 40 years. 



Eii>e age 40 t(i GO years. 



Senility beyond CO years. 



We give these figures as a concession to custom and to make the succession of the periods 

 more easily appreciated. But let us hasten to add that they arc for the most part very uncertain. 



First period of childhood. — From liirth to the eruption of the firsl great mohus, calh'd sixth 

 year's teeth. » • • 



Second period of childhood. — It conmiences at about the age of six years witli tlie eruption of 

 the first permanent molar, which marks the beginning of the secimtl dentition; it ends al»out the 

 age of thirteen or fourteen years, when the eruption of the four second i)ermanent molars is com- 

 pletely achieved. • • • 



Youth. — It commences when the eruption of the four second permanent mohirs is completely 

 achieved — that is to say, when the crowns of these teeth are altogether on a level with those of the 

 first molars; it is finished when on the one hand the wisdom teeth are come out, and when on the 

 other hand the basilai- suture is completely closed. 



Adult (ii/e, ripe ai/e, and .scniliti/. — Onward from the end of the third period the distinction ot 

 ages is much more doubtful. It is based upon the observation of two phenomena which arc 

 gradual and very irregular in their chronology. * * * 



Physiologically one is generally contented to divide all the time which i)asses fnmi the end of 

 youth to death into two periods: The period of gradual change, called indifferently virility, adult 

 age, or rijjc age, and the period of decadence, called senility. In cianiology tlu' first of these 

 periods should be divided in two ages: Adult age, com[)rised between the end of youth and the 

 beginning of the ossification of the sutures, and the period of gradual change from then on to 

 senility. The craniological distinction between adult age and ripe age is generally easy since it 

 rests upon the anatomical observation of the study of the sutures. * • * 

 Senility of the; skull is recognized by the following characters: 



First. Tlu^ sutures are mostly in an advanced or complete state of ossification; some of them 

 at least are entirely effaced and may have left not even a vestige. The others, with the exce]>tion 

 of the scpiamous suture, which sometimes remains open until a very advanced age. are moic or 

 less ossified. • • • 



' Instructions craniolo;;i<iiiL's et cranioiiietriinus par 1'. ISroca, Paris, 1875, pi). IL'S cl suq. 



285 



