70 TRANSACTIONS OF THE 



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skull and other bones of the head would render the horizon- 

 tal support of the head extremely difficult. The strict laws 

 of mechanical equilibrium, therefore, operating cumulatively 

 through the joint action of both these causes would tend to 

 elevate the forepart of the body until the spine should be- 

 come vertical, the head be borne directly over this bony 

 axis, the fore limbs completely exempted from duty as organs 

 of locomotion, and the hind limbs devoted exclusively to 

 that purpose. 



Respecting the important attribute of speech it was main- 

 tained that it is the result of mental far more than physical 

 development. The larynx of many animals, and particu- 

 larly of the ape family, is known to be highly developed. 

 The true reasons why these animals do not possess articulate 

 speech is because they do not possess sufficient intelligence 

 to invent and employ arbitrary sound-symbols. That they 

 cannot be expected to perform so high an intellectual feat 

 was exemplified by the fact that microcephalous idiots hav- 

 ing a brain capacity of less than sixty cubic inches are in- 

 capable of being taught to speak, although they possess a 

 well developed larynx and behave in all respects like tamed 

 Animals, while the orang, whose brain is larger than that of 

 any other ape, has an encephalon of only thirty-five cubic 

 inches. 



Thus, without any violent assumptions, it was shown that 

 all the differences which separate the highest animals from 

 the lowest human races can be accounted for by the natural 

 laws of adaptation as now understood by naturalists. 



The three questions of the unity, the local origin, and the 

 antiquity of the human race were then briefly considered. 

 The first may now be regarded as temporarily, if not per- 

 manently, settled on the monophyletic basis. The second 

 cannot be expected to be settled, or even placed, in a way of 

 enlightened discussion, until the tropical regions of Asia and 

 Africa shall have been thoroughly explored by paleontolo- 

 gists. As to the third enough is already known to enable 

 us to class man along with many other of the higher mam- 



