ADAPTATION TO ENVIRONMENT 



257 



DISTRIBUTION OF PRIMATI 



^n 



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theory" of Wallace, of an exclusively northern land connection 

 of the eastern and western hemispheres during Tertiary time, 

 has recently been maintained by Matthew^ as adequate to 

 explain all the chief facts of mammalian migration and geo- 

 graphic evolution. 



The feet and the teeth of mammals become so closely 

 adapted to the medium in which they move and the kind of 

 food consumed that 

 through the interpreta- 

 tion of their structure 

 we shall in time write a 

 fairly complete physio- 

 graphic and climatic his- 

 tory of the Tertiary 

 Epoch along the lines of 

 the investigations in- 

 itiated by Gaudry and 

 Kowalevsky. Through 

 the successive adapta- 

 tions of the limbs and 

 sole of the foot and the 

 adaptations of the teeth, 

 which are most delicately 

 adjusted — the former to impact with varying soils and the 

 latter to the requirements of the consumption of various forms 

 of nourishment — we may definitely trace the influences or 

 rather the adaptive responses to the habitat subzones, such as 

 the forest, forest-border, meadow, meadow-border, river-border, 

 the lowland, the upland, the meadow-fertile, the meadow-arid, 

 the plains, and the desert-arid. This mirror of past geography, 

 climate, evolution of plant life in the anatomy of the limbs 



Fig. 122. The North Polar Theory of the 

 Distribution of Mammals. 



A zenith view of the earth from the north pole, 

 showing (arrows) the North Polar theory of the 

 geographic migrations and distribution of the 

 mammals, especially of the Primates (monkeys, 

 lemurs, and apes). After W. D.Matthew, 1915. 



Matthew, W. D., 1915. 



