64 Formation of Species. 



through natural selection. And as other species 

 may, in the same way, be reduced to a single 

 primitive form, it is clear that the number of 

 original species will be exceedingly limited. In 

 deed, some naturalists hold that all the organic 

 beings which have ever lived on this earth may 

 be descended from some one primordial form. 

 And even the cautious Darwin maintains that all 

 &quot; animals are descended from at most only four 

 or five progenitors, and plants from an equal or 

 lesser number.&quot; 



In this genealogical table of all living beings 

 man cannot be separated from the apes. Both 

 are modified descendants of the same progenitors. 

 This deduction from Darwin s theory of natural 

 selection, now, is confirmed by a comparison of 

 the two species. In the first place, their struct 

 ure is not only on the same fundamental plan, 

 but presents a complete correspondence of parts. 

 If you compare the gorilla with man, you will 

 find, it is true, that its brain-case is smaller, its 

 trunk larger, its lower limbs shorter, its upper 

 limbs longer, in proportion, than those of man ; 

 but in all these respects the other apes depart 

 still more widely from the gorilla. And what 

 ever organ or system of organs be selected for 

 comparison, whether the vertebral column, the 



