LIFE HISTOEIES OF NOBTH AMEBICAN DIVING BIBDS. 203 



He says further : 



When the auks deposit their eggs along with the guillemots, which they some- 

 times do, they drop them In spots from which the water can escape without 

 injuring them ; but when they breed in deep fissures, which is more frequently 

 the case, many of them lie close together, and the eggs are deposited on small 

 beds of pebbles or broken stones raised a couple of inches or more, to let the 

 water pass beneath them. CaU this Instinct If you will ; I really do not much 

 care, but you must permit me to admire the wonderful arrangements of that 

 nature from which they have received so much useful knowledge. When they 

 lay their eggs in such an horizontal cavern as that which I have mentioned 

 above, you find them scattered at the distance of a few Inches from each other; 

 and there, as well as in the fissures, they sit flat upon them like ducks, for 

 example, whereas on an exposed rock, each bird stands almost upright upon 

 its egg. Another thing quite as curious which I observed is, that while in 

 exposed situations the auk seldom lays more than one egg, yet In places of 

 greater security I have, in many instances, found two under a single bird. This 

 may, perhaps, astonish you, but I really can not help it. 



Eggs. — The razor-billed auk never attempts to raise more than 

 one young bird in a season and never lays but a single egg, I believe, 

 unless the first one is taken, when, of course, it will keep on laying. 

 Two eggs have frequently been found together and are probably 

 in such cases incubated by a single bird, but I believe that, in such 

 cases, the two eggs have been accidentfUy rolled together or have 

 been laid by two birds. Some specimens of the eggs closely resem- 

 ble certain types of eggs of the murres, but they can usually be 

 easily recognized. They are less pointed, as a rule, and are never 

 really pyriform. In shape they vary from " elliptical ovate " to 

 " elongate ovate." They also never show the deep blue colors of 

 the murres' eggs. The ground color varies from " pinkish buff " to 

 " ivory yellow " or " Marguerite yellow " in some specimens, but more 

 often it is a very pale bluish white or greenish white and often dull 

 pure white. The markings are variable in size, shape, density, 

 and arrangement; sometimes the egg is fairly evenly covered with 

 small spots and sometimes it is boldly blotched and scrawled; 

 frequently the markings are confluent in a ring around the larger 

 end. The colors in the markings are only the darker shades of 

 brown, from " warm sepia " or " bone brown " to black ; frequently 

 there are inconspicuous, underlying spots of various shades of 

 lavender, lilac, or gray. The texture of the shell is coarse, thick, and 

 lusterless. The measurements of 80 eggs in the United States Na- 

 tional Museum average 75.9 by 47.9 millimeters; the eggs showing 

 the four extremes measure 83.5 by 48, 78.5 by 51.5, 69 by 48.5, and 

 75 by 42 millimeters. 



Young. — ^The period of incubation is about 30 days and both 

 sexes incubate. Audubon (1840) says that the young have " a lisp- 

 ing note " and are " fed freely on shrimps and small bits of fish, the 

 food with which their parents supply them. They were very friendly 



