io Habit and Instinct. 



on the wing. And Mr. F. M. Chapman says * that these 

 birds " are the most expert fly-catchers he has ever 

 seen. Their watchfulness permits no insect to pass in 

 safety. They maintain a constant look-out, turning the 

 head quickly from side to side. The dart into the air is 

 made with wonderful celerity. Sometimes it is straight 

 up, again at various angles, and they go as far as thirty or 

 thirty-five feet from their perch, to which they return after 

 each sally." Fly-catchers, as a rule, have short bills and 

 a broad gape. Why, then, is the long pointed bill preserved 

 in these jacamars ? Mr. Chapman tells me that they scoop 

 holes in the sand, in which they build their nest, and that 

 they use their bills for this purpose. Hence, perhaps, the 

 retention of the long pointed form. Be that as it may, no 

 one would be likely to predict that the jacamar was one of 

 the most expert of fly-catchers. 



The instinctive activities, which we have now seen to 

 be something more than local responses to stimuli, and to 

 involve the general behaviour of the animals which perform 

 them ; and which, while they are correlated with organic 

 structure, could not in many cases be inferred from the 

 closest morphological or anatomical examination; — are 

 characterized, as was said, by the fact that they are 

 severally common to, and similarly performed by, all 

 the like members of the same more or less restricted group 

 of animals. Knowing the instinctive activities which are 

 characteristic of the life-history of the great water-beetle or 

 other organism, you may be sure that they are common to, 

 and similarly performed by, all the like members of the 

 species, the qualification like members being introduced to 

 cover the divergencies of instinctive behaviour due to sex. 



It must not be supposed, however, that this constancy 



* " Chapman on the Birds of Trinidad," Bulletin Am. Mus. of Nat. Hist., 

 vol. vi., 1894, p. 63. 



