At the time in the earth's history when water, in a liquid state, made its appearance on the cooled crust of the earth, the carbon probably existed as carbonic acid dispersed in the atmosphere; and from the very best of grounds, it is reasonable to assume that the density and electric condition of the atmosphere were quite different, as also the chemical and physical nature of the primeval ocean was quite different. In any case, therefore, even[15] if we do not know anything more about it, there remains the supposition, which can at least not be disputed, that at that time, under conditions quite different from those of to-day, a spontaneous generation, which is now perhaps no longer possible, may have taken place. This point is now conceded by most all of the advanced scientists of the day, and is absolutely necessary for the completion of the hypothesis of evolution. The answer may come to this--Well, suppose the first protoplasm did originate by spontaneous generation, where did the elements or force come from which compose it? Science has nothing to do with the coming into existence of matter or force, for she proves both to be indestructible; when they disappear, they do so only to reappear in some other form. The coming into existence of matter and force, as also the ultimate cause of all phenomena, is beyond the domain of scientific inquiry. Science has only to do with the coming in of the form of matter, not the coming in of its existence. [Illustration: FIG. I.--A Moneron (Protamoeba) in act of reproduction; _A_, the whole Moneron, which moves like ordinary Amoeba, by means of variable processes: _B_, a contraction around its circumference parts it into two halves; _C_, the two halves separate, and each now forms independent individuals. (Much enlarged.)--_Haeckel._] [Illustration: FIG. II.--_A_, is a crawling Amoeba (much enlarged).--_Haeckel._ The whole organism has the form-value of a naked cell and moves about by means of changeable processes, which are extended from the protoplasmic body and again drawn in. In the inside is the bright-colored, roundish cell-kernel or nucleus. _B_, Egg-cell of a Chalk Sponge (Olynthus).--_Haeckel._] [Illustration: FIG. III.--Represents the next higher stage, Mulberry-germ or Morula (Synamoeba).--_Haeckel._] THE COMING INTO EXISTENCE OF MAN, BY THE SLOW PROCESS OF DEVELOPMENT. It is necessary now to take up the little mass of living matter, admitting its coming into existence by spontaneous generation as probable, and so probable that it almost amounts to a certainty, and follow it through the many changes it is about to make under the influence of the laws which govern evolution until it has culminated in man, and these laws still acting on the brain of man, perfecting it, and leading him on to the comprehension of a grander and nobler conception of the Almighty and of his works.