...he Who Remains Passive When Over-whelmed With

... If Variations Useful To Any Organic Being Do Occur, Assuredly Individuals Thus Characterized Will Have The Best Chance Of Being Perserved In The Struggle For Life; And From The Strong Principle Of Inheritance They Will Tend To Produce Offsping Similarly Characterized. This Principle Of Preservation, I Have Called, For The Sake Of Brevity, Natural Selection.

You Ask About My Opinion On Vivisection. I Quite Agree That It Is Justifiable For Real Investigations On Physiology; But Not For Mere Damnable And Detestable Curiosity.

I Fully Agree With All That You Say On The Advantages Of Spencer's Excellent Expression Of 'the Survival Of The Fittest.' This, However, Had Not Occurred To Me Till Reading Your Letter. It Is, However, A Great Objection To This Term That It Cannot Be Used As A Substantive Governing A Verb; And That This Is A Real Objection I Infer From H. Spencer Continually Using The Words, Natural Selection.

One General Law, Leading To The Advancement Of All Organic Beings, Namely, Multiply, Vary, Let The Strongest Live And The Weakest Die.

Hence, A Traveller Should Be A Botanist, For In All Views Plants Form The Chief Embellishment.