But from the ontogenic record no chapter can be torn out: a fresh copy of the whole history, from alpha to omega, is written out every time an infant is conceived, and born, and grows to manhood. And somewhere on the way between the first cell of the embryo and maturity each one must repeat in his own life that wonderful transition into human intelligence. If we can thoroughly decipher tills ontogenic record, then, what may we not hope to learn of the road by which we human beings came? We must not forget that the correspondence between these life books is only a rough one. They are versions of the same world story, but they have traveled far from their common origin, and have become widely unlike in details. The baby has to take many short cuts, and condense and omit inconceivably, to get through in a few brief years a development that the race took ages for. Even the order of development gets disarranged sometimes. For instance, primitive man probably reached a higher development before he could talk than babies have to now, after ages of talking ancestry: we must not look to a child just learning to talk, to get an idea of what the minds of men were like when _they_ were just learning to talk. Again, the human child is carrying on under the influence of adults an evolution that primitive man worked out without help or hindrance from any one wiser than himself; and that makes a great difference in the way he does it. The moral of all this is that people should be very cautious indeed in drawing parallels between the child and the race, and especially in basing educational theories on them. But if one is cautious enough and patient enough, there are many hints about our race history to be found in every nursery. Some of these I shall relate in the following chapters. * * * * * Most studies of children deal with later childhood, the school years; and these are almost always statistical in their method, taking the individual child very little into account. My own study has been of babyhood, and its method has been biographical. It is hard to get statistics about babies, scattered as they are, one by one, in different homes, not massed in schoolrooms. Now and then a doctor has found material for good comparative investigations, and much effort has been spent in trying to gather up measurements of babies’ growth; but on the whole the most fruitful method so far has been the biographical one--that of watching one baby’s development, day by day, and recording it.