228 L. Manouvrier — Pithecanthropus erectus. 



mode of locomotion in harmony with an adaptation instinctively 

 and organically fixed. 



One hypothesis among others would be the destruction, 

 more or less complete, of the forests on an island inhabited by 

 anthropoids capable of taking, when necessary, the biped atti- 

 tude. The ancient volcanoes of Java might have accomplished 

 this destruction and have rendered necessary the adaptation to 

 the upright position under pain of extinction of the race. 



It would be impossible to explain easily the disappearance of 

 an anthropomorphous species as much superior to all others as 

 was that of the individual from Trinil ; for it was strongly 

 built with a cerebrum superior to all known species of the order 

 of Primates. It possessed, then, excellent chances of survival 

 in the struggle for life. But, on the hypothesis here con- 

 sidered, the species Pithecanthropus erectus would not have 

 disappeared. Having become a human race, it could not 

 remain at the same time a race anthropoid. If the Pithecan- 

 thropus was only a simple precursor, it was superior enough to 

 the other animals to survive unless the human species, spring- 

 ing up all of a sudden, " from the clay of the earth," did not 

 hasten to annihilate this dangerous competitor. But if the 

 Pithecanthropus was an ancestor, its species lives yet in its 

 human descendants. 



The difference between the Pithecanthropus and existing 

 man is so small that there is no call to search for an intermedi- 

 ate link. The link is sufficiently represented by the lowest of 

 our savage races; for example, the isolated human skulls, Aus- 

 tralian and others, that have already been shown to be very 

 little different in many respects from that of Trinil. 



Supposing that among several species of gibbon, Ga?, Gy, 

 Gs ; this latter species evolved toward the human type and 

 became finally, in assuming the upright position, the Pithecan- 

 thropus erectus =H 1 , then that it, by virtue of the multiple 

 consequences of the upright position, became progressively H 2 , 

 a stage corresponding to the lowest existing races, we obtain in 

 simplifying : 



Gibbon x 

 Gibbon y 

 Gibbon z— ^-(P.E.^H^-H 2 . 



There ought to be then in the existing fauna a hiatus formed 

 by the transformation of the gibbon z into H°, then of H° into 

 H 1 , so that, in this existing fauna, the species nearest to H 2 

 ought to be a species very inferior, issue of gibbon x or y. 

 The gap here ought to be all the greater in that it is not only 

 a question of a transformation such as that of one quadruped 

 into another, conserving the generic characters of its ancestor ; 



