CONTINUITY IN EVOLUTION 333 
responses, and from the coalescence of their results into a 
conscious situation. To a quite young chick I gave pieces of 
yellow orange peel, which were found to be distasteful and 
rejected. In Dr. Stout’s phraseology, they acquired meaning 
in experience. Can one doubt that the colour and taste were 
thus rendered predominant, and that the shape, size, and other 
qualities of the bits of orange peel remained practically un- 
noticed ? Shortly afterwards the chick was given chopped 
and crumbled egg ; the fragments of “ white” were eaten, but 
the bits of hard-boiled yolk were untouched. They possessed 
a sufficient general resemblance to the orange peel to carry the 
same meaning. In many ways particular qualities of objects 
are emphasized in so far as they incite to behaviour ; they form 
centres of biological interest, just as the abstract quality of 
ideational thought is the centre of rational interest on a higher 
plane of mental development. And in many ways objects present- 
ing certain salient features in common, amid differences which 
remain unnoticed, are unconsciously grouped as the starting- 
points of similar perceptual situations, just as in the generaliza- 
tion of ideational thought similar relationships are deliberately 
grouped as the starting-points of like conceptual situations. 
Both are purposive and have an end, which we as investigators 
are able to assign; but only for reflection and conceptual 
thought are they also purposeful—the end being foreseen and 
realized, not only by the investigators, but by the agent con- 
cerned. And the purpose or end itself is in the two cases 
different. In the one case it is the biological end of practical 
behaviour ; in the other case it is the rational end of explana- 
tion—abstraction and generalization being deliberately used as 
a means to this latter end. The question has again and again 
been asked : Do animals reason? And different answers are 
given by those who are substantially in agreement as to the 
facts and their interpretation, but are not in agreement as to 
their use of the word “reason.” Perhaps, if the question 
assume the form—Are animals capable of explaining their own 
acts and the causes of phenomena ?—the position of those who 
find the evidence of their doing so insufficient may be placed in 
