26 FORM AND HABIT: THE TAIL. 



This singular habit is practiced by numerous species 

 of Motmots, ranging from Mexico to Brazil. It is there- 

 fore of undoubted age, and we can only speculate upon 

 its use and origin. Young birds from the nest, reared 



FIG. 11. Central tail-feathers of Motmot (Momotus subrufescens), showing 

 newly grown feathers (at the left) and results of self-inflicted mutilation. 



in confinement where they were isolated from others of 

 their kind, trimmed their tail-feathers soon after they 

 were grown.* 



The habit, therefore, is inherited, but the mutilation, 

 although it has doubtless been practiced for countless 

 generations, has not become inherent, unless we consider 

 the constriction in the vane of the feather at the place 

 where it is to be trimmed an indication of inheritance. 



The Motmot gesticulates with its tail in a remarkable 

 manner, swinging it from side to side, so that it suggests 

 the pendulum of a clock, or sweeping it about in circles 

 with a movement which reminds one of a bandmaster 

 nourishing his baton. We shall find in other species, 

 also, that the tail, more than any other organ, is used to 

 express emotion. Recall its twitching and wagging ; how 

 it is nervously spread or "jetted," showing the white 



* See Cherrie, The Auk (New York city), vol. ix, 1892, p. 322. 



