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 Hdinger 
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 cther 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- 
tamide) of Australia, the hornbills (Bucerotide), of the East Indies, 
and to the honey-guides (Indicatorine), of the Hast Indies and Africa. 
