_Büchner._ Nothing is easier, sir. For “there is exhibited (in the terrestrial strata) a constant relation of the external conditions of the surface of the earth to the existence of organic beings, and a necessary dependence of the latter on the condition of the earth” (p. 64). “It was only with the present existing differences of climate that the endless variety of organic forms appeared which we now behold.... Of man the highest organic being of creation, not a trace was found in the primary strata; only in the uppermost, the so‐called alluvial layer, in which human life could exist, he appears on the stage—the climax of gradual development” (p. 65). _Reader._ How does this show that “organic life developed itself” and was a mere result of the development of the earth? It seems to me that your answer has no bearing on the question, and that it is, on your lips, even illogical. For you say somewhere: “It is certain that no permanent transmutation of one species of animals into another has as yet been observed; nor any of the higher organisms was produced by the union of inorganic substances and forces without a previously existing germ produced by homogeneous parents” (p. 68). This being _certain_, as you own, I ask: If every organism is produced by parents, whence did the parents come? Could they have arisen from the merely accidental concurrence of external circumstances and conditions, or were they created by an external power? In your theory, they must have arisen from external circumstances, and therefore they had no parents; whilst you affirm that without homogeneous parents they could not naturally be produced. Moreover, if the first parents arose from a concurrence of external conditions, why does not the same happen today? _Büchner._ “This question has ever occupied philosophers and naturalists, and has given rise to a variety of conflicting opinions. Before entering upon this question, we must limit the axiom _Omne vivum ex ovo_ to that extent that, though applicable to the infinite majority of organisms, it does not appear to be universally valid” (p. 69). _Reader._ Then you evidently contradict yourself. _Büchner._ “At any rate, the question of spontaneous generations is not yet settled” (_ibid._) _Reader._ Do you mean that living organisms can be produced without previously existing homogeneous parents, or germs, merely by the concurrence of inorganic elements and natural forces? _Büchner._ Yes, sir; and “although modern investigations tend to show that this kind of generation, to which formerly was ascribed an extended sphere of action, does not exactly possess a scientific basis, it is still not improbable that it exists even now in the production of minute and imperfect organisms” (p. 70). _Reader._ You are cutting your own throat, doctor. For you own that your theory has no scientific basis; and what you say about the non‐ improbability of some spontaneous generations has no weight whatever with a philosophical mind.