EARLY STAGES OF MENTAL DEVELOPMENT - 55 
similar vole; and the chief difference lies in the fact that 
less stereotyped congenital behaviour is supplemented by 
some guidance, probably far less than is generally supposed, 
from those who lovingly min'ster to the course of infant 
development. 
No attempt can here be made to trace even in outline (an 
outline which must in any case be imaginary and conjectural) 
the sequence of situations which marks the course of mental 
development in its earlier stages. An example may, however, 
serve to show how the exercise of congenital tendencies may 
give rise to a new situation, and lead to a further developmeut 
of behaviour. 
I kept some young chicks in my study in an improvised pen 
floored with newspaper, the edges of which were turned up and 
supported, to form frail but sufficient retaining walls. One of 
the little birds, a week old, stood near the corner of the pen, 
pecking vigorously and persistently at something, which proved 
to be the number on the page of the turned-up newspaper. 
He then transferred his attention and his efforts to the corner 
of the paper just within his reach. Seizing this, he pulled at 
it, bending the newspaper down, and thus making a breach in 
the wall of the pen. ‘Through this he stepped forth into the 
wider world of my study. I restored the paper as before, 
caught the bird, and replaced him near the scene of his former 
efforts. He again pecked at the corner of the paper, pulled it 
down, and escaped. I then put him back as far as possible 
from the spot. Presently he came round to the same corner, 
repeated his previous behaviour, and again made his escape. 
Now, here the inherited tendency to peck at small objects 
led, through the drawing down of the paper, to a new situa- 
tion, of which advantage was taken. The little drama con- 
sisted of two scenes, which may be sufficiently described as 
“the corner of the pen,” and “ the open way,” this being the 
sequence in experience. Subsequently the first scene was 
again enacted in presentative terms, and there followed first 
a re-presentation of scene ii., with its associated behaviour, 
and then the presentative repetition of this scene. We may 
