DUCKS' BACKS 315 



at once from the dark -backed Tufted Duck, even though 

 the latter wears his white flank-feathers so high that 

 they almost meet in the middle of the back. By the 

 way, did you ever notice a curious difference between 

 the Pochard and the Tufted Duck ? The former has a 

 complete " turtle back," while the latter has a well- 

 marked longitudinal depression running the whole 

 length of it. 



If you have not noticed this, just look the next time 

 you are at the Zool. Gardens. I don't know how it is 

 with the Scaup or White-eyed Duck, perhaps betwixt 

 the two. 



