He then quoted in its entirety a section from pages 381 to 388 of the Appendix. This lacked a heading, but in the Contents appeared as "Accommodation of organized life to circumstance, by diverging ramifications". In it, he commented on the difficulty of distinguishing "between species and variety". The change of the fossil record between geological eras implied living organisms having "a power of change, under a change of circumstances", in the same way as the "derangements and changes in organised existence, induced by a change of circumstance from the interference of man" gave "proof of the plastic quality of superior life" which he called "a circumstance-suiting power". Following past deluges, "an unoccupied field would be formed for new diverging ramifications of life" in "the course of time, moulding and accommodating their being anew to the change of circumstances". He proposed that "the progeny of the same parents, under great difference of circumstance, might, in several generations, even become distinct species, incapable of co-reproduction."