16 ORGANIC EVOLUTION — PHYSICAL 



retrogressed by the way, and that those that reached 

 the farthest limits, did not remain altogether unchanged, 

 but changed somewhat as ages passed and generations 

 lived and died ; those that remained in the original 

 habitat having changed least, those that wandered 

 farther having changed more, and those that wandered 

 farthest having changed mo^t, and this for the reason 

 that though the environment nowhere remained abso- 

 lutely unaltered, yet for those that travelled farthest it 

 altered most ; so those Aryans who dwell in or near the 

 original habitat of the race have changed least, those 

 who halted by the way have changed more, and those 

 that journeyed farthest to the West, or diverged to the 

 North or South, have changed most. So also in the 

 march of life, the lowest organisms may be considered 

 as having stayed behind at or near the original starting- 

 point ; the sponges as having diverged from the main 

 road at an early period ; the Ccelenterates, the Mol' 

 ~^lusks, the Annulosa to have halted by the way at a 

 later stage ; whereas the Vertebrates, with mammals at 

 their head, and man at the head of the mammals, may 

 be considered as having reached the farthest limits. 

 But just as it becomes increasingly difficult the farther 

 we penetrate into historical antiquity to trace the 

 descent of the nations of any race of human beings, 

 — the Teutonic for example, — not only for the reason 

 that the peoples who have travelled farthest have 

 changed so much, have undergone evolution, and 

 because the peoples who halted by the way or stayed 

 behind have changed also, but because some of the 

 links of the chain are broken, because some of the 

 nations which halted by the way are lost and cannot be 

 recognized, or because they have perished utterly in the 

 struggle for existence ; so also the farther we penetrate 

 into geological antiquity, the harder it becomes to trace 

 the descent of species, the more numerous become the 



