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have been reduced considerably, and the 2"'^ premohxr more than 

 the first. Where as the premohxrs in the upper jaw of all other 

 Catarrhines possess three and in the lower jaw two fangs, the 

 premolars of man have normaliter one single fang. That this 

 has originated from several, appears from the grooves on the 

 surface. Now it is not without significance that the first premolar 

 shows its origine of a form with several fangs, by a dividing of the 

 point of the fang. So P^ is more reduced than P^ with man. If 

 further the milkmolars, which temporarily precede the premolars 

 are compared, we state that the milkmolars differentiate progressively 

 in the group of the catarrhines, and this is especially the case with 

 the second milkmolar. The progression concerns especially the crown 

 of the teeth, the ]uiml)er of roots is two in the lower jaw, three in 

 the upper jaw. 



So if we for a moment fix our attention exclusively on m^ and 

 its replacing tooth P.^ with man, it appears that the first is in 

 pi'Ogression, tlie second in regression, and that with man, the same 

 relation exists in regard to these two teeth as ^vilh m^ and P, of 

 the Platyrrhines. When man namely pushes out his m.-^ and replaces 

 it by Pj, his set of teeth becomes functionally inferior, for instead 

 of a tooth with iwq or four knobs on the crown and two or three 

 fangs there comes in its place a tooth with two cusps on the 

 smaller crown and only one root. 



So we see, that the terminal element of -the dental band of 

 the second generation {P^) reduces with man. Still distinctly' 

 may be seen the terminal reduction of the tooth band, of the 

 first generation, closing with il/j, for as is already mentioned our 

 il/j no longer even issues in ±12 "/o of 'i-H cases, and is always 

 behind in development, at least with more highly developed human 

 races. So the human set of teeth is characterized from the catarrhine 

 Primates by tlie following peculiarities ; the last molar is on its way 

 of reduction, tiie last premolar is on its way of reduction, the last 

 milkmolar has developed very progressively. So a trio of phenomena 

 which are entirely homological to those, by which the catarrhine set 

 of teeth has originated from the platyi-rhine. Only one phase is still 

 wanting to the process, namely the remaining persistent of the last 

 milkmolar and the suppression of the last premolar. And this phase 

 also is reached now and then individually. This among others 

 appears from what Magitot says : La persistance des grosses molai- 

 res temporaires (jhJ s'observe très-souvent, concurremment avec 

 ['absence congenitale ou I'atrophie des secondes prémolaires (P,) 



