On The Origin of Species by Charles Darwin Chapter 8 Page 77

will have had the best chance of succeeding in the struggle for existence.

7. Objections To The Theory Of Natural Selection As Applied To Instincts: Neuter And Sterile Insects

It has been objected to the foregoing view of the origin of instincts that “the variations of structure and of instinct must have been simultaneous and accurately adjusted to each other, as a modification in the one without an immediate corresponding change in the other would have been fatal.” The force of this objection rests entirely on the assumption that the changes in the instincts and structure are abrupt. To take as an illustration the case of the larger titmouse, (Parus major) alluded to in a previous chapter; this bird often holds the seeds of the yew between its feet on a branch, and