When, for instance, the embryo of an animal is formed, it grows; but any one who has observed it internally must have been struck by a fact much more marvelous than that of the visible external "growth." A wonderful internal grouping of the cells takes place; some form, as it were, a leaf which folds over and makes the intestines, others separate to form the nervous system, one group isolates and specializes itself to make the liver, and thus an organization of parts, more and more pronounced, together with a minute differentiation of each individual arrangement of the cells, is carried on. The future functions of the body all depend upon the possibility of the cells so establishing themselves.
The important point is, not that the embryo grows, but that it coordinates. "Growth" comes through and by order, which also makes life possible. An embryo which grows without coordinating its internal organs is not vital. Here we have not only the impulse, but the mystery of life. The evolution of internal order is the essential condition for the realization of vital existence in a life which possesses the impulse to exist.
Now the sum of the phenomena indicated in the "guide to psychological observation" actually represents the evolution of spiritual order in the child.
Guide to psychological observation. Work.—Note when a child begins to occupy himself for any length of time upon a task.
What the task is and how long he continues working at it (slowness in completing it and repetition of the same exercise).
His individual peculiarities in applying himself to particular tasks.
To what tasks he applies himself during the same day, and with how much perseverance.
If he has periods of spontaneous industry, and for how many days these periods continue.