710 THE POPULAR SCIENCE MONTHLY. 



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 comj^ared 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 in. 

 sistence 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. Per- 

 hapsand this is more especially noticeable in the lectures on Evolu- 

 tion 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 illustra- 

 tion 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 recog- 

 nized, 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 be- 

 coming 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, ^es^xr- 

 ornis 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 Hux- 

 ley 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 

 Woi'ld, is even more remarkable for having buried in her soil a greater 



