# Popular Science Monthly/Volume 55/May 1899/Scientific Literature

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SPECIAL BOOKS.
The famous discovery in Java, by Dubois, of the skullcap, femur, and two teeth in the upper Tertiary rocks has led to many interesting discussions, among which was a paper read by Ernst Haeckel before the International Congress of Zoölogists, held in Cambridge, England, last year. In this paper Haeckel contended that in these remains we had at last the long-sought-for missing link. This paper excited much interest, ​which led to a request for its publication. The intelligent public, without knowing much about the value of the osteological points under discussion, were ready to grant that here indeed was the missing link, since the highest authorities in science were divided in opinion as to whether the remains belonged to a very low member of the human race or a very high member of the manlike apes. The conclusion would naturally follow that it made but little difference whether the remains proved to be those of man or monkey, as here was a creature so intermediate in structure that it stood on the dividing line, so to speak. In this little book Haeckel presents the old evidences as to the structural similarities between man and the higher apes, and places the Java remains (Pithicanthropus erectus) as the last link in the chain of descent. He also traces the ancestors of the apes through the mammalian series down, step by step, to the lowest vertebrates, and on through the invertebrates to the lowest forms of life. The suggestions are in many cases hypothetical yet instructive, as showing the possible lines of descent.
The unaccountable attitude of the distinguished Virchow in the presence of these remains is in harmony with his uncompromising and, one might say, unreasoning attitude in regard to the derivative theory. Haeckel shows this up very clearly in the following, which we quote: "Virchow went to the Leyden Congress with the set purpose of disproving that the bones found by Dubois belonged to a creature which linked together apes and man. First, he maintained that the skull was that of an ape, while the thigh belonged to man. This insinuation was at once refuted by the expert paleontologists, who declared that without the slightest doubt the bones belonged to one and the same individual. Next, Virchow explained that certain exostoses or growths observable on the thigh proved its human nature, since only under careful treatment the patient could have healed the original injuiy. Thereupon Professor Marsh, the celebrated paleontologist, exhibited a number of thigh bones of wild monkeys which showed similar exostoses, and had healed without hospital treatment. As a last argument the Berlin pathologist declared that the deep constriction behind the upper margin of the orbits proved that the skull was that of an ape, as such never occurred in man. It so happened that a few weeks later Professor Nehring, of Berlin, demonstrated exactly the same formation on a human prehistoric skull received by him from Santos, in Brazil."
Mr. Russell expresses a hope that the review of some of the characteristics of rivers given in one of the chapters of his Rivers of North America may stimulate a desire in American students "to know more of the many and varied charms of their native land." The study of rivers is an alluring one, whether pursued upon the little local stream of one's neighborhood or upon the grand rivers that form systems and determine geographical districts; whether made with the assistance of a fishing-rod or of a steamboat. It can not fail to be promoted by Mr. Russell's instructive book, which the local student or the excursionist may consult with profit, while the geographer and geologist will find it a convenient manual. A river, when we come to think of it, means a great deal. Economically, it is the most valuable topographical feature a country can possess; geologically and geographically, it is a result of prominent features of the earth's structure, and is the cause of modifications in its surface which in time ​may revolutionize the topographical conditions and produce climatic and physical changes. All these characteristics of rivers are systematically and comprehensively set forth in Mr, Russell's book, where the life-history of the stream is presented, from its beginning in a little mountain torrent or hillside rill, through its course as it descends to the plain, wearing and tearing and deepening its channel. In the plain its character and action are modified under the new conditions in which it finds itself, and gradually, as it approaches its mouth, it deposits, whereas it had torn away at its beginning, and shows contrasts quite as marked as those between youth and old age. Rivers have their growth in time, too, and a stream that has been carrying on its work for long ages presents different characteristics throughout its course from one that comes fresh to its task, and these differences are pointed out. We are told, too, how rivers grow, drawing new affluents to themselves and extending their sources backward, and how when the sources of streams on different sides of a watershed approach on the summit, there is a struggle for the mastery. These are only a few of the new suggestions which the book offers us. Coming to the more matter-of-fact details, the laws governing streams and their course; the influence of inequalities and the hardness of rocks, especially on riverside scenery; and the office of rivers as carriers of material in suspension and in solution, are considered; then their deposits, under various heads and aspects, and the effects of changes in the elevation of the land, of variations in the load of material and of changes of climate upon them; the origin and characteristics of stream terraces and stream development, the topics concerning which are too many and varied to bear more than a passing reference. The more salient characteristics of American rivers are discussed as to the nine drainage slopes—the Atlantic, St. Lawrence, Hudson Bay, Arctic, Bering, Pacific, Great Basin, Gulf, and Caribbean—each slope presenting its own general characteristics, with varieties in detail almost as numerous as the rivers. The whole is briefly summarized in the last chapter. The Life History of a River. We have given merely the tamest inventory of only a part of the topics of Mr. Russell's book. As the subject is treated by the author with careful attention to specific features, as the magnitude of our river systems is indicated, and as rivers with different or contrasting characteristics—the St. Lawrence and the Colorado, for example—are compared with one another, the subject takes on an aspect that is really grand.
* ↑ The Last Link. Our Present Knowledge of the Descent of Man. By Ernst Haeckel. Adam and Charles Black. 1898.
* ↑ Rivers of North America. A Reading Lesson for Students of Geography and Geology. By Israel C. Russell. New York: G. P. Putnam's Sons. Pp.327. Price, $2.