Summary

Believes CD’s argument against special creation based on absence of terrestrial mammals on islands isolated before Pliocene era is very strong. However, the absence means Cetacea and bats have not modified towards terrestrial existence. There is similar lack of development of bats and rodents in Australia. Constancy among land shells of Madeira over long period shows that the majority of their species are immutable: a minority of "metamorphic" species maintains the overall number of true species while extinction removes many. Emphasis on the role of extinction discomfits CD’s opponents since the power of generation of new species ought to keep pace. Mentions Ammonite deposits with reference to CD’s comments on their apparent sudden extinction [Origin, pp. 321–2]. Perhaps absence of transmutation on slowly subsiding atolls indicates the slow rate of selective change.