DERIVATION OF THE FLORA AND FAUNA 421 



Chapter XVI. 

 The biogeographical history of Easter Island. 



The composition of the present fauna and flora does not help us to throw 

 any Hght on the earlier history of Easter Island, and we do not know what they 

 were like before the arrival of aboriginal man many centuries ago. We know that 

 the island became densely populated, that the natural resources, evidently poor, 

 were exploited, the soil cultivated wherever this was possible and a number of 

 useful plants introduced from other parts of Polynesia; tradition tells that the first 

 colonists arrived from Rapa, but other opinions have also been expressed. ROGGE- 

 VEEN, the discoverer of the island in 1722, did not bring a naturalist, but to 

 judge by his narrative the island must have looked much the same as when 

 Sparrman and the FORSTERS, who came with CoOK in 1774, made the first bio- 

 logical observations. Forster collected and cited a few species (346) and men- 

 tions, in his narrative (j^/), "Mimosa" [SopJwra toromiro) and Apiurn, which he 

 had observed before in New Zealand. If there had been other indigenous trees, 

 they had disappeared; Broussonetia papyrifera, Thespesia populnea and very likely 

 also Triunifetta semitriloba had been introduced but were scarce. For wood the 

 natives depended on SopJiora, and most of this was gone already. FORSTER 

 found the place very barren, but on p. 578 he speaks of a hillock covered with 

 toromiro, and later on another similar hill is mentioned (p. 592), but all the trees 

 were low, not over 9 or 10 feet, the main trunk of the biggest as thick as a 

 man's thigh. No wonder that the single canoe seen was a patchwork of pieces 2 

 or 3 feet long, and so was the paddle. The population did not exceed 700. When 

 Thompson and Cooke [343) visited the island in 1886, groups of trees were ob- 

 served in some places: 



In other parts of the island may be seen, in places in considerable numbers, a 

 hardwood tree, more properly bush or brush, called by the natives toromiro. These 

 must have flourished well at one time, but are now all, or nearly all, dead and decaying 

 by reason of being stripped of their bark by the flocks of sheep which roam at will 

 all over the island. None of the trees are, perhaps, over 10 feet in height, nor their 

 trunks more than 2 or 3 inches in diameter (p. 705). 



The last specimens of toromiro are restricted to the inside of the crater Rano 

 Kao. Easter Island was made a national park in order to protect the unique stone 

 monuments, and is a bird sanctuary, but otherwise nature is not preserved but the 

 land grazed over without restriction as far as I am aware. 



Among the many isolated islands of the Pacific, Easter occupies a rather 

 unique position. Oceanic islands belong to two main categories, high volcanic and 

 low coralline; only the former are of greater biological interest and possess the 

 standard set of "peculiarities" described by Hooker, Wallace and others. Easter 

 Island seems to form a type by itself. It is volcanic and cannot be called low, for 

 the highest mountain is 530 m high and some of the craters reach an altitude 



