ABSTRACT
We have already discussed at an earlier stage an important difference between man and animals, the difference, namely, that in many cases animals possess innately faculties which man must acquirel aboriously. Many animals are able to run or swim from their birth; the spider spins its web without example or practice, the bird makes its nest, when the time comes, without ever having seen such a nest before. The caterpillars of many species of butterflies spin a cocoon shortly before the pupa stage; and this may have special arrangements which later aid the butterfly in creeping out. Examples of this kind can be multiplied indefinitely; they all have this in common, that the animals in question are able to exercise a certain activity without example and without learning, and in a perfect manner.
