284 Habit and Instinct. 



it confirms the old instinct, or confirms the new modifica- 

 tion, whether it sets its seal on specific uniformity or leads 

 to somewhat divergent individualism, in either case th< 

 role of intelligence in the establishment of habits is ai 

 important one. 



I must here again insist on the importance of asc 

 taining whether any habit has an instinctive foundation, 

 by observing the young when placed under such conditions 

 that imitation of the parents is impossible. There is 

 curious habit of the niotmot (Momotus), the use of which if 

 quite unknown. It tears off with its somewhat serrate< 

 bill the barbs of the middle pair of tail feathers, in sucl 

 a way as to lay bare the shaft for an inch or so, and 

 make the feathers racquet-shaped. Mr. G. U. Cherrie 

 has shown that this procedure is probably instinctive ; fc 

 it was performed by the young birds (Momotus lessoni] 

 which had been taken from the nest before the tail feathei 

 had grown. Mr. Chapman kindly showed me younj 

 specimens in which these feathers, still immature, had n< 

 been thus trimmed. There appeared to be a slight line 

 of weakness along the bases of the barbs where they 

 would in due time have been torn away. He suggested 

 the possibility that there was some slight obstruction here 

 to the drawing of the feathers through the bill. Perhaps 

 the line of weakness causes these barbs to catch in the 

 serrations of the bill. Such catching would no doubt draw 

 the bird's attention to the feathers in question, and lead 

 to a frequent repetition of the habit. In the adult motmot 

 the tail is kept in constant jerky motion as the bird utters 

 a cooing note, and the peculiar trimming of the central 

 feathers may have a sexual import. In any case, Mr. 

 Cherrie's observation as to the treating of the feathers in 

 this way, with little opportunity of imitation, is of interest ; 



* The Auk, 9, p. 323. 



