L. Manouvrier — Pithecanthropus er edits. 229 



but of a transformation of the attitude even, that is to say of 

 morphologic conditions entailing a radical change of type and, 

 indirectly, of physio-psychologic modifications very profound. 



The existence of a hiatus between two related living species 

 cannot then serve as argument against the theory of evolution. 

 This hiatus, as we have just seen, may be, on the contrary, a 

 direct result of the transformation of one species into another. 



Although the transformation here supposed has been very 

 profound, enough so to give birth to a pretended new "king- 

 dom, " human kingdom," that transformation could have been 

 produced, according to the above hypothesis, without compelling 

 Nature to make, in any sense, a leap. It may be possible, from 

 a point of view purely zootaxic, to establish a veritable saltus, 

 but I have just shown that this saltus could have been the 

 gradual consequence of a simple modification of habits of 

 locomotion in a race of monkeys already capable of assuming 

 the upright position. The motive for this change could have 

 arisen abruptly, but there has been no anatomic leap from 

 Gibbon z to existing man. That which can have been pro- 

 duced abruptly is the exterior condition from which would 

 have resulted, for an anthropoid race of climbers, the necessity 

 of adopting habitually a mode of locomotion which it was 

 already capable of utilizing occasionally. The only thing 

 abrupt, from a biologic point of view, would have been a sim- 

 ple increase in the frequency of the utilization of a functional 

 aptitude already existing. Multiple and considerable anatomic 

 modification may have been entailed by this change of the 

 habitual attitude, but they ought to have been produced by 

 insensible degrees and are all the less astonishing in that the 

 anthropoids already approach much nearer to man than to 

 monkeys proper in their general conformation (Huxley, 

 Broca). 



If there is a gap between the existing human species and 

 the precursor, the fossil remains of the intermediate races 

 ought none the less to exist. There ought to be the remains 

 of H°, of gibbon z and of Prothylobates. Will these last 

 perhaps reveal a species remarkable in stature and in a rela- 

 tively superior aptitude for the upright position % That is not 

 necessary theoretically: the diverse species of the genus 

 Hylobates have a conformation which enables them to assume 

 the upright position with ease ; the form may have undergone 

 considerable variations after the transformation of the attitude. 



Finally, it is probable that the species gibbon z approached 

 man in certain respects more than do known species of the 

 genus Hylobates. 



However, if we admit that the pieces found at Trinil really 

 represent the remains of a Pithecanthropus, and if it is admitted 



Am. Jour. Sol— Fourth Series, Vol. IV, No. 21.— Sept., 1897. 

 16 



