the effect produced after a very short space of time. It would, therefore, be reasonable to conclude that the effect of thousands of years' association—as in the case of rocking with sleep in arboreal dwellers—would still be found to influence children very long after arboreal life had been abandoned.
It is certainly singular to find that nursery ditties contain reference to matters arboreal, as if there was some lingering tradition in the human race of ancestors who lived in trees. Thus the English mother or nurse in rocking her infant to sleep sings:
Lullaby baby on the tree top;
When the wind blows the cradle shall rock;
When the bough breaks the cradle will fall,
And down will come baby, cradle, and all.
Somewhat similar is a German nursery ditty:
Schlafe, schlaf ein, mein Kind.
Horch! da draussen der Wind;
Wie das Vöglein im grünen Baum,
Wiegt er auch dich in süssem Traum.
Nowhere is a stage of a former arboreal life, with its consequent climbing instinct, manifested more conspicuously than in the insane desire of an infant to climb upstairs. As soon as crawling is an accomplishment the climbing of stairs is attempted. Remain on the level and crawl about rooms the child will not; it must make for the nearest stairs to climb with loud crows of delight. Tumbles and consequent bruises have no effect on the child's climbing instinct, and really it regards them far less than the prohibition of its climbing feats by a too fond and foolish mother. It is better to let the child climb. Even a fall down the whole flight of stairs only checks the climbing mania temporarily, in order that the infant may loudly express its disapprobation of its own clumsiness, and may vent its anger in howls. But this episode over, it will, within a quarter of an hour, bravely attack the stairs again, having quite forgotten its late disaster. An instinct held so tenaciously can not be regarded as something fortuitous. Darwin considered that the tree-climbing propensity of boys was a relic of monkey ancestors, but he made no observation on the stair-climbing instinct of infants. Mothers, unfortunately, do not always possess enough scientific calmness to watch an infant climb stairs with every chance of a tumble, so they are apt to cut short such experiments. But if left alone—and that is the best plan—it is remarkable how soon the child learns not to tumble; and then the mother need have no more fear.
The early efforts of a child in learning to walk indicate the habits of an animal to whom the upright position is something
