THE STORY OF THE ISLANDS. 217 



this very subject of islands shows the way of reform. 

 Science, in this sense, dives below the bare facts of 

 the text-book, and seeks to give reasons for these facts. 

 It places itself in the position of an expositor and 

 expounder of the manner in which our world and its 

 affairs have come to assume their existing order. 



Geographically, all islands are regarded as of much 

 the same constitution. They are detached masses of 

 land, surrounded by sea, and differing, to the mind of 

 the school-boy or school-girl, chiefly in size. Australia 

 is a big island ; Madagascar is not so big ; and from 

 Ceylon onwards to Mauritius or the Azores there are 

 found all degrees and gradations of magnitude. This, 

 with a few details about the quarters of the world in 

 which islands exist, and with some ideas about pro- 

 ducts and peoples, complete the geographical know- 

 ledge of the average man and woman. Science takes 

 up the matter where commonplace geography ends its 

 story. It asks, first of all, what islands really are, 

 and how one island differs from another. 



As the result of its investigations, science soon dis- 

 covers that islands may be divided by their nature into 

 two distinct sets or classes. Of these two divisions, 

 the first includes islands which can lay claim to that 

 title from the first day of their existence, in that they 

 have never formed part and parcel of any larger mass 

 of land. Thus we first distinguish the so-called 

 " volcanic" islands, which, like the Azores, have been 

 thrust up from the sea-depths by volcanic action, to 

 form detached masses of land existing, it may be, 

 many miles from a continent or mainland. 



Then comes a second class of islands which are 

 called " continental," because, whatever their size, 

 form, or situation, we can prove them to be, geologi- 



