primitive instincts of the vertebrates. They are the bedrock
foundations upon which every species rests. As they are stable or
unstable, good or bad, so lives or dies the individual, and the
species also.

In employing the term "highest animals" I wish to be understood as
referring to the warm-blooded vertebrates, and not merely the apes
and monkeys that both structurally and mentally are nearest to
man.

Throughout my lifetime I have been by turns amazed, entertained
and instructed by the marvelous intelligence and mechanical skill
of small mammals in constructing burrows, and of certain birds in
the construction of their nests. Today the hanging nest of the
Baltimore oriole is to me an even greater wonder than it was when
I first saw one over sixty years ago. Even today the mechanical
skill involved in its construction is beyond my comprehension. My
dull brain can not figure out the processes by which the bird
begins to weave its hanging purse at the tip end of the most
unstable of all earthly building sites,--a down-hanging elm-tree
branch that is swayed to and fro by every passing breeze. The
situation is so "impossible" that thus far no moving picture
artist has ever caught and recorded the process.

Take in your hand a standard oriole nest, and examine it
thoroughly. First you will note that it is very strong, and
thoroughly durable. It can stand the lashings of the fiercest
gales that visit our storm-beaten shore.

How long would it take a man to unravel that nest, wisp by wisp,