presence of primitive organisms, but no record of any of the higher forms of life. In 1906 I collected fossil shells of lowly invertebrates from the early Paleozoic rocks of Wisconsin. During the spring of 1916 I found the remains of somewhat higher types of invertebrates in slightly younger rocks of the same era in eastern Ontario and later described these fossils in publications of the Ontario bureau of mines and in the Ottawa Naturalist. Other invertebrate fossils of about the same age and about the same kinds were observed when I was in Bolivia in 1919 and 1920. Accompanied by half-bred guides and camp hands I, together with K. C. Heald, formerly chief of the oil and gas section of the United States geological survey, pushed far beyond the outposts of civilization into the rocky fastnesses of the eastern Andies and there we found these fossil remains.
Saw Evidences in Rocks.
I have seen the fossil remains of primitive fishes of middle Paleozoic age on a number of occasions near Columbus, Ohio; in 1917, in Allen County, Kentucky, and in 1919, in Sumner County, Tennessee. I observed the foot prints of large reptiles in rocks formed shortly after the upheaval of the Appalachian Mountains at several places in the Connecticut valley during 1921. While exploring in Alaska during the summer of 1923, I searched for fossils in rocks of middle Mesozoic age, but found in them only the remains of shellfish and corals. There was a party of six dispatched by the United States geological survey to search for mineral resources in a previously unknown and altogether uninhabited portion of the Alaska peninsula, not far from the famed valley of Ten Thousand Smokes, so named because of the countless vents from which steam roared heavenward. We had to cut steps with our geologic hammers across glaciers and snow fields in traversing the almost inaccessible mountains of that bleak, barren and rugged land. In Colorado, during the summer of 1924, I had occasion to study the petrified bones of mammals imbedded in flat-lying rocks of Cenozoic age directly overlying tilted strata of late Mesozoic age, in which were the fossil bones of reptiles. The tilting of those beds was a part of the crustal movement which formed the Rocky Mountains; the flat layers on top of them were deposited while those mountains were being eroded.
To this summary of known facts concerning the life of the past, there might be added a multitude of other facts concerning the body structures of the various animals, the life history of the individual animal from its start as a single fertilized cell until its attainment of adult stature, etc. have, however, personal knowledge of only a few of the facts in these fields in which I am not a specialist. While exploring the headwaters of the Amazon in Bolivia and Peru in 1919 and 1920, I lived for some time among quite uncivilized peoples, many of whom had never before seen a white man. At the same time I watched the habits and examined the bodies of several different kinds of South American monkeys. I have studied with care the skeletons of many of the Asiatic apes and Old World monkeys, as they were available in various university laboratories and museums. From these studies and from the studies of others, I can affirm the following generalized statements: Comparing the body structure of monkeys, apes and man, it is apparent that they are all constructed upon the same plan; with only trivial exceptions every bone in the body of one has its counterpart in the body of the others. Only in details of shape, in relative size and in method and angle of articulation with their neighbors do these bones differ in the different creatures just mentioned. Monkeys have long tails; some apes have long and some have short tails; man has a vestigial tail composed generally of about four vertebrae so small and so short as to be entirely concealed in the flesh and muscles at the base of the
