[105] In his valuable and comprehensive _Geschichte der Geologie und Paläontologie_ (1899), Prof. K. von Zittel, while referring to Lamarck's works on the tertiary shells of Paris and his _Animaux sans Vertèbres_, also giving a just and full account of his life, practically gives him the credit of being one of the founders of invertebrate palæontology. He speaks of him as "the reformer and founder of scientific conchology," and states that "he defined with wonderful acuteness the numerous genera and species of invertebrate animals, and created thereby for the ten years following an authoritative foundation." Zittel, however, does not mention the _Hydrogéologie_. Probably so rare a book was overlooked by the eminent German palæontologist. [106] _History and Methods of Paleontological Discovery_ (1879), p. 23. CHAPTER X LAMARCK'S OPINIONS ON GENERAL PHYSIOLOGY AND BIOLOGY Lamarck died before the rise of the sciences of morphology, embryology, and cytology. As to palæontology, which he aided in founding, he had but the slightest idea of the geological succession of life-forms, and not an inkling of the biogenetic law or recapitulation theory. Little did he know or foresee that the main and strongest support of his own theory was to be this same science of the extinct forms of life. Yet it is a matter of interest to know what were his views or opinions on the nature of life; whether he made any suggestions bearing on the doctrine of the unity of nature; whether he was a vitalist or not; and whether he was a follower of Haller and of Bonnet,[107] as was Cuvier, or pronounced in favor of epigenesis. We know that he was a firm believer in spontaneous generation, and that he conceived that it took place not only in the origination of his primeval germs or _ébauches_, but at all later periods down to the present day. Yet Lamarck accepted Harvey's doctrine, published in 1651, that all living beings arose from germs or eggs.[108] He must have known of Spallanzani's experiments, published in 1776, even if he had not read the writings of Treviranus (1802-1805), both of whom had experimentally disproved the theory of the spontaneous generation of animalcules in putrid infusions, showing that the lowest organisms develop only from germs. The eighteenth century, though one of great intellectual activity, was, however, as regards cosmology, geology, general physiology or biology, a period of groping in the dim twilight, when the whole truth or even a part of it was beyond the reach of the greatest geniuses, and they could only seize on half-truths. Lamarck, both a practical botanist, systematic zoölogist, and synthetic philosopher, had done his best work before the rise of the experimental and inductive methods, when direct observation and experiments had begun to take the place of vague _à priori_ thinking and reasoning, so that he labored under a disadvantage due largely to the age in which he lived.