ENDONOMIC SELECTION ILLUSTRATED. 63 
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the lower classes of animals, largely physiological, with some coodrdi- 
nated instincts; while in the case of man the power of adjustment is 
very largely psychological, and in the case of the other classes of ani- 
mals, above the lowest, physiological and psychological adaptations 
constantly codperate. The explanation of these inherited adapta- 
tions of the humblest organism to climatic and other conditions in- 
volving great fluctuations is, I think, to be found in the fact that they 
or their ancestors were gradually introduced to these alternations, 
and that selection has thus had an opportunity to work for countless 
generations in producing the corresponding complex adaptations and 
powers of accommodation. It may be granted that man and his 
ancestors have consumed an equal succession of ages in attaining the 
inherited intellectual constitution that fits him for his higher sphere, 
without lessening our apprehension of the wonderful contrast between 
man and all lower organisms, in his power to enter suddenly upon a 
new set of conditions. This power is so great that man may suddenly 
enter a new territory, furnishing not a single product that he can eat, 
and by his art of agriculture so completely meet his needs that he 
becomes a permanent settler without even subjecting himself to any 
new form of selection. Jn other words, accommodation is in some cases 
so complete that coincident selection is prevented. This suggests that 
am some spheres of activity, councident (that is, organic) selection, ts less 
liable to occur in man than wm animals whose accommodation is less 
complete. 
8. Endonomic Selection tllustrated by Several Species of North American Birds. 
By means of accommodation birds and beasts determine their rela- 
tions to the environment, and so determine the kind of selection to which 
they and their descendants are thereajter subjected. The choice of con- 
ditions that have brought pleasant experiences and the avoidance 
of those that have brought unpleasant experiences is a degree of 
intelligence enjoyed by many species of animals, and is a form of 
accommodation that may determine the mode of life and so deter- 
mine the forms of selection. For example, the cliff swallow, rang- 
ing over most of North America, has accommodated itself to the new 
conditions introduced during the past two centuries by the occu- 
pation of the country by house-building people. Except in a few of 
the Western States, where the population is sparse and the houses 
few, it has deserted the cliffs and taken up its abode under the eaves 
of the houses, thus bringing itself into very close connection with man 
and subjecting itself to some forms of selection which it might have 
