138 THE POPULAR SCIENCE MONTHLY 



by students in recent years, by the Hampton Court maze or labyrinth 

 method, upon young chicks, and various wild species, show an ability 

 to learn more or less rapidly, according to the simplicity of the path 

 to be traversed. They always seem to be guided in large measure by 

 sight. Their educability has been further tested by Thorndike and 

 others, by placing food within sight, but enclosed in a wire box, access 

 to which can be reached only by working some simple contrivance, with 

 bill or foot, such as pecking or pulling at a string. The animal is thus 

 induced to do an unusual thing, or to do it in an unusual way, but some 

 species, like the house sparrow, have proved apt to learn, and though 

 success may come first through accident, by the tenth or some later trial, 

 the new act is learned, and unnecessary movements are in time elim- 

 inated. The effect of the acts performed, as in the case of exit from 

 the labyrinth, is remembered for days or weeks, according to the strength 

 of the habit, or the ability of the learner. Whether the memory in- 

 volved in these and similar acts is of a visualized character, involving 

 a memory idea, image or picture, may be doubted, though Edinger 

 among others is not inclined to admit this. We might ask why a bird, 

 with a memory image of the position of her nest, does not always strike 

 a direct path to it, after reaching her tree. Why should she slavishly 

 follow the track stamped in by previous associations, walking along a 

 certain branch, and grasping a certain twig, before landing at the nest- 

 side, a practise very commonly followed? Such behavior certainly can 

 not always be attributed to the inhibitory effect of fear. 



All the intelligence which birds may on occasion exhibit seems to 

 give way under the spell of any of the stronger instincts, as when the 

 male canary, as related by Blackwell, plucked the feathers from the 

 necks and backs of its own young in order to line a newly built nest, 

 although ether feathers were supplied to it in abundance. They seldom 

 meet emergencies by doing the intelligent act, and, in spite of the anec- 

 dotes, probably but seldom come to the effective aid of their compan- 

 ions when in distress. On the other hand, I have more than once seen 

 a mother bird try to pluck a hair or piece of grass from the mouth of 

 a nestling. 



It has been asserted that only birds can be frightened from fields by 

 scarecrows, but to most birds any strange object is a " scarecrow," which 

 may in time, and often brief at that, become familiar through associa- 

 tion, as shown by the many devices used by farmers to frighten crows 

 from their fields of newly planted corn. The genuine scare crow is a 

 subject worthy of further study. 



At this point I wish to notice certain anomalous actions of peculiar 

 interest in birds, and to refer particularly to the wood swallows (Ar- 

 tamid?e) of Australia, the hornbills (Bucerotidas), of the East Indies, 

 and to the honey-guides (Indicatorinag), of the East Indies and Africa. 



