the Shaft in the Motmofs Tail. 339 



deteriorated in strength, so that they were not pecked away. 

 It seems therefore that the natural weakness of the vanes 

 liad been further increased through that of the bird itself, 

 and also because an extra strain had been put upon feather- 

 production through the plucking of those tail-feathers which 

 had only lately grown, just as one sees feathers in weakly 

 birds become white, owing to a deficiency in the vigour of 

 the blood with a consequent loss of colouring pigments. 

 Therefore, to my mind, it would seem that in the case of 

 INfr. Beebe's Motmot, the deterioration which is perhaps 

 gradually taking place through many ages was, as it were, 

 artificially hastened and brought about. 



The Racquet-tailed Parrots, and I presume the Kingfishers 

 also that have these ornamental tail-feathers, grow the 

 racquets with a portion of the shafts already bare of any 

 barbs, and this narrowing and weakening of the barbs in the 

 central tail-feathers of the Motmots may be working towards 

 this in the far future. 



I have never seen my Motmot, when preening his feathers, 

 touch the extremities of his tail-feathers with his bill — ■ 

 indeed, it would almost seem as if he were unable to do 

 so, for, owing to the feet being very small in proportion to 

 the bird, after the style of a Kingfisher or a Roller, any 

 extra exertion in preening is apt to overbalance the bird ; 

 so that, for instance, he only just manages to scratch the 

 sides of his head by a rapid movement of the uplifted foot, 

 and it is evident that his balance would be lost off his perch 

 if he did not immediately return the foot to grasp it, 

 as I have frequently seen happen. Magpies and other 

 birds with long tails, such as the Indian Sham ah, can and 

 do preen the entire length of the feathers, and one has 

 often watched the process ; but in the case of my Motmot, 

 I have never seen him go beyond the shorter lateral feathers 

 of the tail. 



Be this as it may, my idea remains that the bird does not 

 pick off the barbs above the racquets, but that they fall off 

 without any aid on the part of their wearer. 



Not until the entire moult is complete does this come 



z2 



