The tropic bird is a species of gull, about the size of a partridge.  It has a red bill and legs.  The feathers are white, tipped with black, and the back is variegated with curved lines of black.  The tail consists of two long, straight, narrow feathers, almost of equal breadth during their whole length.  Their flight is most graceful--they glide along with scarcely any perceptible motion of the wing.  They return every night to roost on land.  They live entirely on fish.  The natives of the South Sea Islands ornament their persons with their feathers.  We saw a number of snakes, but none of them attempted to bite us; and the doctor said from their appearance that he did not believe them to be of a venomous character.  Whenever we went near the water among the rocks, we saw large fish darting about, of every colour and shape; huge, long eels gliding in and out between the rocks, and fierce, voracious sharks pursuing their prey.