OUR FACE FROM FISH TO MAN 



partly outward as well as forward. But in all the 

 more advanced lemuroids the eyes are larger, with 

 more or less protruding orbits which tend to shift 

 forward, finally restricting greatly the interorbital 

 space and nasal chamber. This process culmi- 

 nates in the nocturnal galagos and in Tarsius 

 (Fig. 31), in which the eyes are enormous and the 

 eyes themselves are directed forward, although 

 the orbits are directed obliquely outward. 



In none of the lower primates, however, are the 

 bony orbits directed fully forward and in none of 

 them are the upper jaws prolonged downward 

 beneath the eyes, as they are in the monkeys, 

 apes and man. 



The families of man, apes, monkeys, tarsioids, 

 lemurs and tree-shrews are exceedingly rare as 

 fossils except in a few localities and geologic 

 horizons and the known remains usually consist 

 chiefly of broken jaws with a few teeth. Never- 

 theless these fossils are of high value when studied 

 together with the manifold families, genera and 

 species of primates still living. In a series of 

 publications beginning in 1910 I have shown how 

 fully these recent and fossil forms, from tree- 

 shrews to man, reveal the structural stages in the 



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