884 Dynamic Theory. 



Wild habits also survive in tame birds. "The sheldrake (Tadorna) 

 feeds on the sands left uncovered by the tide, and when a worm-cast is 

 discovered it begins patting the ground with its feet, dancing as it were, 

 over the hole, and this makes the worm come to the surface. Now Mr. 

 St. John says, that when his tame sheldrakes came to ask for food, 

 they patted the ground in an impatient and rapid manner. This, there- 

 fore, may almost be considered as their expression of hunger. Mr. 

 Bartlett informs me that the flamingo and the kagu (rhinochetus ju- 

 batus) when anxious to be fed beat the ground with their feet in the 

 same odd manner. So again, kingfishers when they catch a fish always 

 beat it until it is killed, and in the zoological gardens they always beat 

 the raw meat with which they are sometimes fed, before devouring it." 

 (Darwin, Emotions 47). 



We often speak of the instincts of animals as unerring ; but this is a 

 mistake. If a man wishes to jump a ditch, he instinctively estimates 

 its width and regulates the force necessary to carry him over. If it is 

 a little too wide and he has to make a run for it, he instinctively esti- 

 mates the length of the run, and regulates his steps so as to bring the 

 right foot upon the spot from which the spring is to be made. In such 

 things as these the instincts of other animals are like our own, some 

 better and some worse. But in the more complicated instincts which 

 include cerebral memories, and involve many organs, the lower animals 

 are by no means infallible. For example, the instinct of a rattle-snake 

 encourages him to attack a hog, with invariable disaster, to the snake. 



The migratory instinct which has been fastened upon large numbers 

 of birds, fishes, and mammals, including some races of men, by the 

 changes in the seasons, is complicated with conscious memories. A 

 bird from Spain will find the same nest in an English hedgerow that it 

 occupied last year. The instinct of direction in Indians and half- 

 breeds has been mentioned. Wrangel observed the remarkable per- 

 fection of it among the natives of North Siberia in finding their way 

 through a labyrinth of ice hummocks, and continually changing direc- 

 tion without getting lost. The wild goose in going north travels in the 

 night and across the ocean. Still this instinct is not unerring either in 

 man or other animal. The Indian packers of an engineer's outfit in 

 northern Wisconsin all got lost one cloudy day. European birds get 

 lost and reach the Azores sometimes, and North American birds lose 

 their bearings and stray to Ireland. Swallows often get lost. Fishes, 

 too, get off the track. Salmon frequently get into the wrong river, 

 " many Tweed salmon being found in the Forth." Certain sheep in 

 Scotland and Spain want to migrate every spring, as no doubt their wild 

 ancestors did. 



The instincts of insects are similar in their nature to those of other 



