Our Descent, Then, Is The Origin Of

The Lower Animals, On The Other Hand, Must Have Their Bodily Structure Modified In Order To Survive Under Greatly Changed Conditions. They Must Be Rendered Stronger, Or Acquire More Effective Teeth Or Claws, In Order To Defend Themselves From New Enemies; Or They Must Be Reduced In Size So As To Escape Detection And Danger. When They Migrate Into A Colder Climate They Must Become Clothed With Thicker Fur, Or Have Their Constitutions Altered. If They Fail To Be Thus Modified, They Will Cease To Exist.

Multiply, Vary, Let The Strongest Live And The Weakest Die.

Consequently, If My Theory Be True, It Is Indisputable That Before The Lowest Silurian Stratum Was Deposited, Long Periods Elapsed, As Long As, Or Probably Far Longer Than, The Whole Interval From The Silurian Age To The Present Day; And That During These Vast, Yet Quite Unknown, Periods Of Time, The World Swarmed With Living Creatures. To The Question Why We Do Not Find Records Of These Vast Primordial Periods, I Can Give No Satisfactory Answer.

Much Love Much Trial, But What An Utter Desert Is Life Without Love.

It At Once Struck Me That Under These Circumstances Favourable Variations Would Tend To Be Preserved, And Unfavourable Ones To Be Destroyed.