Guests, Welcome and Unwelcome 201 



the humming-bird, on the wing, scarcely ever setthng, and 

 making a humming noise with its wmgs. 



The jessamine is probably fertilized by the hawk-moth, 

 which hovers in like manner; but jessamine-seed is rare in 

 England, for hawk-moths are rare, too. But the want of 

 hawk-moths may not be the sole reason for the scarcity 

 of seed. The humble-bees are also in some measure to 

 blame, for they come to the blossoms in search of nectar, 

 and finding no perch upon which they can stand to suck 

 in the proper way — the only way to benefit the flower — 

 they get what they want by gnawing through the tube of 

 the corolla, which soon drops in consequence. 



Flowers which open at night are of course especially 

 dependent upon night-flying moths; and as colors would 

 not be seen, they are generally white or pale yellow, and 

 have no lines to show where the nectar is, for these also 

 would not be visible; but they are often so sweet as to be 

 scented from afar. The large white bindweed, though 

 it opens by day, remains open at night, when the 

 moon shines, but not otherwise, to receive the visits of 

 moths. 



Wherever, in any part of the world, there is a dearth 

 of bright-colored flowers, there, as a rule, is a scarcity 

 of insects, and vice versa, for where insects are wanting, 

 there the flowers fertilized by them cannot of course 

 flourish. 



The scarcity of both these is very conspicuous in the 

 Galapagos Islands, situated on the equator, some seven 

 hundred miles west of South America. In Juan Fernan- 

 dez also, which lies about four hundred miles off Chili, 

 ferns form the larger part of the vegetation, as they do in 

 most of the South Sea Islands. But there is no such 



