Variation Quotes

One [method] is by a Watch to keep time exactly. But, by reason of the motion of the Ship, the Variation of Heat and Cold, Wet and Dry, and the Difference of Gravity in different Latitudes, such a watch hath not yet been made.

I have called this principle, by which each slight variation, if useful, is preserved, by the term of Natural Selection.

Variation under Domestication,' there are two factors: namely, the nature of the organism, and the nature of the conditions.