Biology and Its Makers / With Portraits and Other Illustrations

by William A. Locy

The work, however, that approached more nearly to scientific demonstration was that of Steno (1638-1686), a Dane who migrated to Italy and became the court physician to the dukes of Tuscany. He was a versatile man who had laid fast hold upon the new learning of his day. Eminent as anatomist, physiologist, and physician, with his ever active mind he undertook to encompass all learning. It is interesting that Steno—or Stensen—after being passionately devoted to science, became equally devoted to religion and theology, and, forsaking all scientific pursuits, took orders and returned to his native country with the title of bishop. Here he worked in the service of humanity and religion to the end of his life.

In reference to his work in geology, his conclusions regarding fossils (1669) were based on the dissection of the head of a shark, by which means he showed an almost exact correspondence between certain glossy fossils and the teeth of living sharks. He applied his reasoning, that like effects imply like causes, to all manner of fossils, and clearly established the point that they should be regarded as the remains of animals and plants. The method of investigation practiced by Steno was that "which has consciously or unconsciously guided the researches of palæontologists ever since."

Although his conclusions were well supported, they did not completely overthrow the opposing views, and become a fixed basis in geology. When, at the close of the eighteenth century and the beginning of the nineteenth, fossil remains were being exhumed in great quantities in the Paris basin, Cuvier, the great French naturalist, reëstablished the doctrine that fossils are the remains of ancient life. An account of this will be given presently, and in the mean time we shall go on with the consideration of a question raised by the conclusions of Steno.

Fossil Deposits Ascribed to the Flood.—After it began to be reluctantly conceded that fossils might possibly be the remains of former generations of animals and plants, there followed a period characterized by the general belief that these entombed forms had been deposited at the time of the Mosaic deluge. This was the prevailing view in the eighteenth century. As observation increased and the extent and variety of fossil life became known, as well as the positions in which fossils were found, it became more difficult to hold this view with any appearance of reason. Large forms were found on the tops of mountains, and also lighter forms were found near the bottom. Miles upon miles of superimposed rocks were discovered, all of them bearing quantities of animal forms, and the interpretation that these had been killed and distributed by a deluge became very strained. But to the reasoners who gave free play to their fancies the facts of observation afforded little difficulty. Some declared that the entire surface of the earth had been reduced to the condition of a pasty mass, and that the animals drowned by the Deluge had been deposited within this pasty mass which, on the receding of the waters, hardened into rocks.

The belief that fossil deposits were due to the Deluge sensibly declined, however, near the close of the eighteenth century, but was still warmly debated in the early part of the nineteenth century. Fossil bones of large tropical animals having been discovered about 1821, embedded in the stalagmite-covered floor of a cavern in Yorkshire, England, some of the ingenious supporters of the flood-theory maintained that caves were produced by gases proceeding from the bodies of decaying animals of large size; that they were like large bubbles in the crust of the earth, and, furthermore, that bones found in caverns were either those from the decayed carcasses or others that had been deposited during the occurrence of the Flood.

Even the utterances of Cuvier, in his theory of catastrophism to which we shall presently return, gave countenance to the conclusion that the Deluge was of universal extent. As late as 1823, William Buckland, reader in geology in Oxford, and later canon (1825) of Christ Church, and dean (1845) of Westminster, published his Reliquiæ Diluvianæ, or Observations on the Organic Remains Attesting the Action of a Universal Deluge.

The theory that the Mosaic deluge had any part in the deposit of organic fossils was finally surrendered through the advance of knowledge, owing mainly to the labors of Lyell and his followers.

The Comparison of Fossil and Living Animals.—The very great interest connected with the reëstablishment of the conclusion of Steno, that fossils were once alive, leads us to speak more at length of the discoveries upon which Cuvier passed his opinion. In the gypsum rocks about Paris the workmen had been turning up to the light bones of enormous size. While the workmen could recognize that they were bones of some monsters, they were entirely at loss to imagine to what kind of animals they had belonged, but the opinion was frequently expressed that they were the bones of human giants.

Cuvier, with his extensive preparation in comparative anatomy, was the best fitted man perhaps in all the world to pass judgment upon these particular bones. He went to the quarries and, after observing the remains, he saw very clearly that they were different from the bones of any animals now existing. His great knowledge of comparative anatomy was founded on a comprehensive study of the bony system as well as the other structures of all classes of living animals. He was familiar with the anatomy of elephants, and when he examined the large bones brought to light in the quarries of Montmartre, he saw that he was confronted with the bones of elephant-like animals, but animals differing in their anatomy from those at present living on the earth.

The great feature of Cuvier's investigations was that he instituted comparisons on a broad scale between fossil remains and living animals. It was not merely that he followed the method of investigation employed by Steno; he went much further and reached a new conclusion of great importance. Not only was the nature of fossil remains determined, but by comparing their structure with that of living animals the astounding inference was drawn that the fossil remains examined belonged to forms that were truly extinct. This discovery marks an epoch in the development of the knowledge of extinct animals.