Psychology. 743 
rious traits of instinct, and difficulties in the way of his theory, 
explaining all of them, the paper closed with the following gen- 
: eral conclusion :—-“ We have chiefly considered the instinct of 
_ animals under the point of view whether it is possible that they 
_ could have been acquired through the means indicated on our 
theory, or whether, even if the simpler ones could have been thus 
acquired, others are so complex and wonderful that they must 
ve been specially endowed, and thus overthrow the theory. 
Bearing in mind the facts given on the acquirement, through the 
selection of self-originating tricks or modification of instinct, or 
through training and habit, aided in some slight degree by imita- 
tion, of hereditary actions and dispositions in our domesticated ani- 
mals, and their parallelism (subject to having less time) to the 
__ Instincts of animals in a state of nature , bearing in mind that in 
= Astate of nature instincts do certainly vary in some slight degree ; 
3 bearing in mind how very generally we find in allied but distinct 
animals a gradation in the more complex instincts, which show 
_ that it is at least possible that a complex instinct might have been 
4 diffculty tally to be profitable to individuals, I can see no overwhelming 
known—t eory. Even 
simple in hat of the Gils of the hive-bee—we have seen how a 
= with instinctive action may lead to results which fill the mind 
o enl is nishment. Moreover, it seems to me that the very gen- 
limits of the gradation of complexity of instincts within the 
ri the same group of animals, and likewise the fact of two 
: riide cies, placed in two distant parts of the world, and sur- 
Much by wholly different conditions of life, still having very 
for | 'n common in their instincts, supports our theory of descent, 
sne 2 Te explained by it; whereas if: we look at each instinct 
= Simi endowed, we can only say that it is so. The imper- 
Pisin. o mistakes of instinct, on our theory, cease to be sur- 
andae indeed, it would be wonderful’ that far more numerous 
