BIOGRAPHICAL SKETCH lix 
intruders. Even Clepsine sticks more firmly than usual when it is 
over its eggs. 
He sums up this part of the paper with a few general state- 
ments: ‘‘Instinet and structure are to be studied from the com- 
mon standpoint of phyletic descent and that not the less because 
we may seldom, if ever, be able to trace the whole development of 
an instinct. Instincts are evolved, not involyed 
and the key to their genetic history is to be sought in their n more 
general rather than in their later and incidental uses.”” ‘As the 
genesis of organs takes its departure from the elementary struc- 
ture of protoplasm, so does the genesis of instincts proceed from 
the fundamental functions of protoplasm.” 
Taking up now the origin of intelligence he says, “‘Since instinct 
supplied at least the earlier rudiments of brain and nerve, since 
instinct and mind work with the same mechanisms and in the 
same channels, and since instinctive action is gradually super- 
seded by intelligent action, we are compelled to regard instinct 
as the actual germ of mind.” “ We are apt to contrast the extremes 
of instinct and intelligence—to emphasize the blindness and inflex- 
ibility of the one and the consciousness and freedom of the other. 
It is like contrasting the extremes of light and dark and forgetting 
all the transitional degrees of twilight.” ‘Instinct is blind; 
so is the highest human wisdom blind. The distinction is one 
of degree. There is no absolute blindness on the one side, and no 
absolute wisdom on the other. Instinct is a dim sphere of light, 
but its dimness and outer boundary are certainly variable; intelli- 
gence is only the same dimness improved in various degrees. ’’ 
To show how instinct becomes less fixed and choice appears he 
cites the behavior of three species of pigeons, the passenger pigeon, 
the ring dove and the common pigeon. If the egg is removed 
from under the wild pigeon and placed on the side of the nest, the 
bird returning to the nest remains a moment or two only and then 
leaves the nest not to return. The ring dove, on the contrary, 
after some time of perplexity, will return one egg into the nest 
leaving the other out; the common pigeon, after a longer period 
of perplexity and uneasiness, will put both eggs back into the nest. 
There is here a gradual loss of precision of the instinct to leave the 
