354 FIELD ZOOLOGY. 



vegetation, pulled up from the river bottom, and fastened 

 like a tiny raft to the stems of reeds and rushes in shallow 

 water. Upon leaving the nest in the morning, the 

 mother grebe has the curious habit of pulling up from 

 the bottom of the nest some of the grasses and decaying 

 leaves to cover the eggs. During the day, the warmth 

 of the sun's heat on the wet weeds serves to keep the 

 eggs warm until the close of day. When surprised, the 

 mother bird slips off the nest leaving the eggs unpro- 

 tected. She simply hides and seems to make no effort to 

 defend her home. The food of the whole order is mainly 

 fish. The young loons and the grebes are praecocial, and 

 early have somewhat the same skill as the adults in 

 diving and swimming. The auks and the puffins are 

 altricial, and anyone who has tried to enter a puffin's 

 nest knows that the puffin is well able to defend her nest 

 from all intruders. 



This is the lowest order of birds; that is, these birds 

 are farthest removed from the passerine birds as regards 

 nervous organization, functional excellence in many lines 

 instead of one line, and in closeness of relationship to 

 man, both physiologically and economically. All these 

 characteristics the passerine birds possess in the highest 

 degree, and the Pygopodes in the lowest degree. It is 

 also true that these birds come nearest to suggesting 

 reptilian characteristics. Hesperornis, the early Cre- 

 tacean bird of the United States, had the general build 

 of the loons of this order. This shows the continuity of 

 the processes by which the Creator has brought gradually 

 into existence the different types of bird life, from the 

 ancient Archaeopteryx, more like reptile than bird; 

 through Hesperornis, loon in build but incapable of 

 flying ; Ichthyornis with some features of the modern bird ; 



