into a fossil, and its subsequent discovery by a geologist, are occasional accidents; but, although the evidence is much less perfect than we could wish, there is enough of it to convince anatomists that existing animals are all in definite blood-relationship to each other, and to make them, in the investigation of any new animal, study its anatomy with the definite view of finding out its place in the family tree of the living world. When Huxley made his first discoveries, entirely different ideas prevailed. The animal kingdom was supposed to offer a series of types, of moulds, into which the Creator at the beginning of the world had cast the substance of life. These types were independent of each other, and had been so since the beginning of things. Anatomists were concerned chiefly with systematic work, with detecting and recording the slight differences that existed among the numbers of animals grouped around each type. No attempt was made to see connection between type and type, for where these had been separately created there was nothing to connect them except possibly some idea in the mind of the Creator. This apparently barren attitude to nature was stronger in men's minds because it had inspired the colossal achievements of Cuvier, a genius who, under whatever misconceptions he had worked, would have added greatly to knowledge. As we have seen in the first chapter, Huxley, through Wharton Jones, and through his own reading, had been brought under the more modern German thought of Johannes Mueller and Von Baer. He had learned to study the problems of living nature in the spirit of a physicist making investigations into dead nature. In the anatomy of animals, as in the structure of rocks and crystals, there were to be sought out "laws of growth" and shaping and moulding influences which accounted for the form of the structures. To use the technical term, he was a morphologist: one who studied the architecture of animals not merely in a spirit of admiring wonder, but with the definite idea of finding out the guiding principles which had determined these shapes.