3. Since animals and plants have been introduced upon our earth in long succession throughout geologic time, and this in a somewhat regular manner, we have a right to assume that their introduction has been in accordance with a law or plan of creation, and that this may have included the co-operation of many efficient causes, and may have differed in its application to different cases. This is a very old doctrine of theology, for it appears in the early chapters of Genesis. There the first aquatic animals, and man, are said to have been "created;" plants are said to have been "brought forth by the land;" the mammalia are said to have been "made." In the more detailed account of the introduction of man in the second chapter of the same book, he is said to have been "formed of the dust of the ground;" and in regard to his higher spiritual life, to have had this "breathed into" him by God. These are very simple expressions, but they are very precise and definite in the original, and they imply a diversity in the creative work. Further, this is in accordance with the analogy of modern science. How diverse are the modes of production and development of animals and plants, though all under one general law; and is it not likely that the modes of their first introduction on the earth were equally diverse? 4. Our knowledge of the conditions of the origination of species, is so imperfect that we may possibly appear for some time to recede from, rather then to approach to, a solution of the question. In the infancy of chemistry, it was thought that chemical elements could be transmuted into each other. The progress of knowledge removed this explanation of their origin, and has as yet failed to substitute any other in its place. It may be the same with organic species. The attempt to account for them by derivation may prove fallacious, yet it may be some time before we turn the corner, should this be possible, and enter the path which actually leads up to their origin. Lastly, in these circumstances our wisest course is to take individual species, and to inquire as to their history in time, and the probable conditions of their introduction. Such investigations are now being made by many quiet workers, whose labours are comparatively little known, and many of whom are scarcely aware of the importance of what they are doing toward a knowledge of, at least, the conditions of creation, which is perhaps all that we can at present hope to reach. In the next chapter we shall try to sum up what is known as to man himself, in the conditions of his first appearance on our earth, as made known to us by scientific investigation, and explained on the theory of creation as opposed to evolution. CHAPTER XV. PRIMITIVE MAN. CONSIDERED WITH REFERENCE TO MODERN THEORIES AS TO HIS ORIGIN (continued).