272 



THE POPULAR SCIENCE MONTHLY. 



recalled by different portions of the skeleton. 

 Amouj^r recent birds, the peculiar legs and feet 

 of Unfiterornis find their nearest analogues in 

 tlic Glebes of the genus Podiceps. They were 

 admirably adapted for propulsion in water, but 

 scarcely served for walking on land. Locomo- 

 tion must have been entirely performed by the 

 posterior limbs a peculiarity which distinguish- 

 es Hesptrornis from all other aquatic birds, re- 

 cent or fossil. Tlie tail appears to have been 

 composed of twelve vertebra;, unique in their 

 peculiar, widely-extended, transverse processes 

 and depressed horizontal plowshare boue. Broad 

 and flat, somewhat like that of the beaver, it 

 must have been a powerful instrument in steer- 

 ing the bird through the water. 



The second part is devoted to a description 

 of the remains which have been found of birds 

 belonging to a second order of Odontornithes, 

 termed Odontotornue. Uulike Hesjjerornis, they 

 Beem to have been all of comparatively small size 

 and to have possressed powerful wings, but very 

 email legs and feet. From that contemporaneous 

 form, and from all other known birds recent and 

 fossil, they are distinguished by certain types of 

 structure which point back to a very lowly an- 

 cestry, lower even than the reptile. Their bones, 

 being mostly air-filled, would enable the car- 

 casses to float on water until, by decay or the ra- 

 pacity of other animals, they were separated and 

 dispersed. Hence skeletons of these flying birds 

 are less entire than those of the massive-boned 

 Eespeivritis. Nevertheless, the remains of no 

 fewer than seventy-seven difi'ereut individuals 

 have been disinterred. These are included in 

 two well-marked genera, Ichthyornis and Apat- 

 ornis, and were all small birds, reminding us by 

 their strong wings and delicate legs and feet of 

 the Terns, like which they were probably also i 

 aquatic in habit. Besides the reptilian skull 1 

 and teeth, the birds of this second order were 

 marked by thecharacterof their vertebra?, which | 

 in their biconcave structure recall those of fishes. 

 This is the more remarkable, as in Uesperornrs 

 the vertebrsE are like those of modem birds. 

 Yet these two utterly dissimilar types were con- 

 temporaries, and their remains have been pre- 

 served in the same strata. Mr. Marsh points 

 out that the transition between the two verte- 

 bral types may be traced even in the ske>eton 

 of Tchfhyorms itself, where the third cervical 

 vertebra presents a modification in which the 

 ordinary avian saddle-shaped form appears as it 

 were in the act of development from the bicon- 

 cave ichthyic form. 



This memoir and those which will suc- 

 ceed it have a weighty interest as contribu- 

 tions to the doctrine of organic evolution. 

 There is no other possible way of explain- 

 ing the numerous facts than by this theory. 

 Professor Marsh's discoveries are new de- 

 monstrative proofs of the law, which he has 

 done more to confirm by these fossil revela- 

 tions than any other living man, or all con- 

 temporary naturalists put together. 



It remains only to add that the volume 

 in all its elements paper, printing, draw- 

 ing, and engraving is superb. The illus- 

 trations, all executed in New Haven, and by 

 the most skillful hands the world aifords, 

 are the perfection of art. Professor Geikie 

 pays them the following high but deserving 

 compliment : " They are strictly and rigidly 

 scientific diagrams, wherein every bone and 

 part of a bono is made to stand out so clear- 

 ly that it would not be difficult to mold a 

 good model of the skeleton from the plates 

 alone. And yet, with this faithfulness to 

 the chief aim of the illustrations, there is 

 combined an artistic finish which has made 

 each plate a kind of finished picture." 

 Should the series of memoirs of the Pea- 

 body Museum of Yale College, of which this 

 is the first, be carried out on a scale and 

 with a thoroughness here attained, it will 

 form one of the great scientific monuments 

 of the century. 



German Thought. By Karl Hillebrand. 

 New York : Henry Holt & Co. 1880. 

 Pp. 298. Price, %\.1b. 



In these six lectures before the Royal 

 Institution of Great Britain, Professor Hil- 

 lebrand has traced in outline the rise of 

 modern German thought and its influence 

 in forming modern German political life. 

 The period covered by his review is that 

 from the Seven Years' war to the death of 

 Goethe, but he glances briefly at the part 

 taken by the other nations in the work of 

 modern culture, as an indispensable pre- 

 liminary to the subject proper. His review 

 leads him to a consideration of the Italian 

 Renaissance, in which Italy led the way in 

 breaking from the thralldom of media;val 

 tradition and authority ; the reaction against 

 the sensuous view of life that this introduced, 

 which in Spain was expressed by the found- 

 ing of the Society of Jesus, and in Germany 

 by the Reformation ; and the passing to Eng- 

 land and Holland, and later to France, of the 

 leadership in the thought and spirit that have 

 made modern Europe. Though Germany 

 held an important place in the initial move- 

 ment, she took but little part. Professor Hil- 

 lebrand points out, in the subsequent prog- 

 ress of it. She had been engaged in one 

 of the most notable struggles in history, and 

 came out of it prostrate. The Thirty Years' 



