We shall learn in the subsequent chapters, that by a careful study of the fauna and flora the fact can be established, not only of the former connection of an island with a continent, but also whether such union existed (geologically speaking) within recent or more remote times. The better the fauna is known, both recent and fossil, the more precisely can the period of connection be indicated, and its duration determined.
FOOTNOTES:
[1] The numbers in brackets throughout this work refer to the page-number in the Bibliography at the end.
[2] A map giving its exact distribution in Ireland will be found on p. [300], and a figure of the slug on p. [298].
[3] The term endemic will be employed throughout this work as applied to species peculiar to a country and not found elsewhere. Autochthonous will be used in speaking of a species which has originated in a country to which, however, it is not peculiar; e.g., the Chamois is an autochthonous Alpine species, but occurs also in the Pyrenees and Caucasus. An indigenous species is one native to a country, as opposed to the term "introduced," and is applicable to all species which have reached it by ordinary migration.
[4] I might refer any one more specially interested in these introductions to an article on this subject in the Irish Naturalist of March 1898, by Mr. Barrett-Hamilton.
[5] I should recommend those who are particularly interested in the full history of the Irish frog to read the notes on this subject contained in vol. ii. of the Irish Naturalist.