Page:Popular Science Monthly Volume 11.djvu/730

710 with the Loan Collection of Scientific Apparatus at South Kensington in December, last year, and deals with the study of Biology.

The range of topics thus indicated is wide enough to give us samples of all the moods of Prof. Huxley's vigorous and eloquent style. As compared with his previously-published addresses and essays, we find no diminution of power, no less artistic care in the arrangement of materials, no less cogency of argument and stern insistence on the appeal to facts rather than to a priori considerations, nor can we detect any indication that as he grows older the author is more timid in face of those "logical consequences" of his teaching—the bugbears of some, but the beacons of other, philosophers. Perhaps—and this is more especially noticeable in the lectures on Evolution—there is less of that playful treatment of opponents and their transgressions—that sudden but graceful discomfiture of his adversary by the unexpected production of a quaint though close-fitting illustration—which in former writings gave a pungency and aroma to Prof. Huxley's pages no less fascinating than peculiarly their own.

In the three lectures on Evolution, the history of Nature is made the subject of a closely-reasoned inquiry. Three current hypotheses—the Uniformitarian, the Miltonic, and the Evolutional—are recognized, and their respective claims to our acceptance discussed. The paleontological evidence in favor of the hypothesis of Evolution forms the subject of the second and third lectures, and with great skill the opportunity is used in order to bring before an American audience in the most forcible way two very important and interesting American discoveries of recent date. America is, indeed, rapidly becoming the headquarters of paleontological research. Prof. Huxley's own discoveries regarding the genealogical connection of birds and reptiles form an important argument in favor of the hypothesis of Evolution, and in placing this argument before his audience he was able to explain to them at some length the interesting new fossil birds obtained by Prof. Marsh, of Yale College, from the cretaceous rocks of Western America. The structure of two of these birds, Hesperornis and Icthyornis which possessed, unlike all other birds, distinct conical teeth imbedded in their jaws, is illustrated by woodcuts in the printed lecture. Now that the principle has been admitted, we may hope to see an illustrated edition of some of the lectures which were issued in preceding volumes without woodcuts.

The second American discovery which is brought to bear on the hypothesis of Evolution, and forms, indeed, part of what Prof Huxley calls the "demonstrative evidence of Evolution," relates to the pedigree of the horse, and is also due to Prof. Marsh. Strangely enough, America, which within the historic period is remarkable for the absence of indigenous horses, and the fertility within her borders of the wild-horses descended from domesticated ancestors of the Old World, is even more remarkable for having buried in her soil a greater