GULLS AND DIVERS 7.7 



sarily leave the throat white. It is just as if the 

 black - headed gull were called white - headed in 

 winter, and two species made out of one. 



It is quite possible that similar mistakes may 

 have crept into our natural histories. The weak- 

 ness of all inquirers is to discern something new ; 

 and, in their eagerness, not to take sufficient pains 

 to verify their conclusions. Before we make 

 additions, it might be as well to revise those we 

 have already made, to assure ourselves that we 

 are not mistaking phases of development from 

 the nestling to the adult, or seasonal changes of 

 plumage to meet the exigencies of the weather, or 

 finery put on for the wedding, as quite another 

 creature, This would still be discovery, entitling 

 the investigator to have his name in the papers, 

 with the further decided advantage of being in the 

 right direction, 



To solve the mystery, a friend went out to shoot 

 a whitethroat, and found the task he had under- 

 taken of no ordinary difficulty. Unlike the 

 buoyant gull, whose whole body seems to be out of 

 the water, and which could not get under the surface 

 if its life depended on it, the diver is so low set that 

 the wavelets lap over his back, until only the neck 

 is visible. Between the firing of the shot, and 



