Dr. Hélan Jaworski may therefore very justly assert that the embryonic period corresponds with the geological period. And, even as, in the great terrestrial evolution, we observe the gradual disappearance of the armour-plated fishes, the monstrous reptiles and the gigantic mammals, so, in the minor embryonic evolution, we see the primitive kidney, the dorsal cord and the umbilical vesicle dissolve, while the liver diminishes and the disproportion between the head and the rest of the body is lessened. In a word, nature is learning wisdom, recognizing her errors, profiting by her experience, doing her best to repair her blunders and acquiring a sense of equilibrium, economy and form. Dr. Jaworski finds other analogies between the geological period corresponding with man’s appearance upon earth and the birth of the child, analogies which are ingenious, but rather more hazardous. Birth is in fact preceded by a miniature deluge, caused by the tearing of the foetal envelopes, which allow the amniotic fluid to escape. Then the child, at the moment of entering into life, suddenly experiences a sort of glacial period; it passes, in fact, from an environment with a temperature of over 98° to the outer air, which is barely 60° or 65°. The sense of cold is so terrible that it wrests a first cry of suffering from the new-born child. 3 What is the meaning of this strange recapitulation? Dr. Jaworski thinks that, if the brief process of embryonic evolution which prepares the way for the birth of man repeats the great process of terrestrial evolution, this latter, on its side, might well be but a vast embryonic period that is preparing for a birth which we cannot as yet imagine. I do not know whether he will succeed in maintaining this stupendous theory. If he does, he will really have made us, as he promises to do, “take a step towards the essence of things.” Meanwhile, thanks to his preparatory studies, he will always have made us take another and a very useful step towards a truth which this time is incontestable, which, though less unexpected, has never been elucidated with so much patience and which is no less big with consequences. 4 Dr. Jaworski, then, undertakes to demonstrate that the human body unites in itself, in a plainly recognizable form, all the living creatures which now exist upon earth and which have existed since the origin of life. In other words, each creature sums up in itself all those which have preceded it; and man, the last-comer, contains within himself the whole biological tree, so much so that, if we could distribute his body, if we could segregate each of his organs and keep it alive in isolation, we should be able to reconstitute all existing forms, to repeople the earth with all the species which it has borne, from the primitive protoplasm to the synthesis, the final achievement, which is man.