AN ISLAND OF WATER 337 



pagos gull and yellow warbler. With only a single 

 sex, permanent establishment and increase would 

 be impossible, but with sea-food for the first two, 

 and flies for the warbler, all would survive for the 

 duration of their lives. In fact at Cocos, I saw a 

 number of mockingbirds and yellow warblers 

 feeding exclusively along the line of tide, picking 

 up tiny shrimps and other forms of marine life. 

 So my island warbler while waiting for the for- 

 lorn hope of an arriving mate, would not have to 

 depend upon the precarious diet of flies, which 

 might have succumbed to the attacks of dragon- 

 flies, or to some more subtle inimical agency. 



Class IV — Pelagic species — This division is 

 merely to visualize the possibilities of three species 

 of petrels, the two shearwaters and the sea turtle 

 coming ashore and making their homes on 

 Seventy-Four, as they could on any oceanic is- 

 land which provided crevices of rocks and, for the 

 chelonian, a sandy beach. 



At the expense of being statistical, but in order 

 to sum up the possible surface and aerial inhabi- 

 tants of my imaginary raised island, I present a 

 census of the complete initial population. 



VEGETABLE KINGDOM 



4 species of living plants of 5 individuals 



ANIMAL KINGDOM 



1 species of fly 12 individuals 



2 species of feather flies 299 " 

 1 species of dragonfly . 20 " 



1 species of ant 1 individual 



