INTRODUCTION TO BIRDS. 255 



Jersey; and these latter represent a later period in the 

 earth's history. The Hesperornis measured about six feet 

 from bill tip to toe end, and must have stood, according to 

 Marsh's restoration, about three feet high. It seems to 

 have been a huge diving bird with the general build of a 

 loon. The Ichthyornis, another find in the same for- 

 mation, was a much smaller bird about the size of a 

 pigeon, and had more of the characteristics of the birds 

 of nowadays. The earliest known bird of the passerine 

 type belonging to the United States, was found in the 

 Florissant Beds of Colorado, those rock beds that have 

 yielded so many specimens of fossil insects also. This 

 bird shows relationships with the immense modern family 

 of the Fringillidae or finches, sparrows as they are more 

 commonly called. To-day, birds are more widely dis- 

 tributed than are any other animals. 



The relationships of birds to man present three 

 phases of study: the scientific, the economic, and the 

 aesthetic. The embryologist, the systematic classifier 

 of animals, the comparative physiologist, and the psychol- 

 ogist, all find abundant material for study among the 

 birds. Among the students of birds may be mentioned 

 Audubon, Coues, Ridgway, Jordan, Goss, Chapman, 

 and a host of lesser students of birds. The labors of 

 these eminent men are of use to the amateur in enabling 

 him to become sufficiently acquainted with birds in their 

 resemblances and differences, to know them in their groups 

 and families, to understand much of their anatomy and 

 physiology, their peculiarities of inter-dependence and 

 relationship among themselves, and the similarities of 

 their sense powers, activities, and behavior to man. 



The economic value of birds to man rests upon the 

 service they render to him in preventing the increase of 



