LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 151 
sprinkled with reddish-brown dots which are thickly concentrated 
into a dense ring of dark brown and reddish brown dots near the 
large end. The measurements of 152 eggs, furnished by Mr. Howell, 
vary in length from 58.5 to 49, in breadth from 38.3 to 33, and aver~ 
age 53.5 by 36 millimeters. 
The period of incubation does not seem to be known, but this duty: 
is evidently performed by both sexes. Mr. Howell (1910) says: 
The old birds not engaged in incubation spend the entire day at sea and are 
not to be seen near the islands. These return after dark, when their mates 
leave for the feeding grounds, and in their turns, reseek the burrows just. 
before the first gray lights of morning. 
Young.—When first hatched the young murrelet remains: in the 
nesting site for perhaps two or three days, never more than four days, 
according to several good observers. As soon as the young bird is 
strong enough, perhaps soon after its down is thoroughly dry, it is 
conducted by its parents to the water and led away to sea. It seems. 
remarkable that such tender young can stand the buffeting that 
they must endure in a rough sea and many of them must lose their 
lives in finding their way through the breakers which surround. 
their rocky birthplace, but perhaps they are safer at sea than on. 
Jand. Mr. Howell writes me, on this subject, as follows: 
When the eggs are once pipped they show amazing vitality. A set that was 
rescued by A. van Rossem and me after having been deserted by the parents. 
among the cold rocks for 36 hours hatched out two lusty youngsters and these 
we succeeded in keeping alive for several days on a diet of hardboiled egg. 
When we substituted bits of fish for this, one died. The other crawled out of the 
tent, tumbled down a cliff, and when discovered, was making his way out to sea 
with all speed. They are surely made for swimming for the tarsus when one day 
old is equal to that of the adults. When in the downy stage they present the most 
attractive appearance of any bird that I know and are truly full of life, hop- 
ping up and down and flapping their little wings from pure joy of life. Upon 
being placed in the water at the age of two days they at once made themselves. 
thoroughly at home. They can then swim as fast as a man usually walks and 
dive at the slightest suspicion of danger, swimming for several yards beneath 
the surface. A large fish rose to one of them twice and the little fellow cleverly 
dodged him. No one as far as I know has ever taken a young hypoleucus om 
land that was more than a few days old. Twelve that I kept under observation 
were taken out to sea before they were 4 days old. H. Wright shot a downy 
young beside an adult several miles from land, and others have observed them. 
How they reach the water is a question, for a murrelet’s bill is not made to 
carry anything so bulky and they could not be carried on the old bird’s back. 
Many must fall a prey to large fish during the first couple of weeks of their 
life and many more die of exposure during heavy winds. Their down, although 
very dense, soon becomes water-soaked and it seems that their only salvation 
would be to climb upon their parent’s back and dry themselves in the sun. 
Plumages.—The downy young murrelet is thickly and warmly clad 
in soft down of fine texture, which is particularly dense on the lower 
parts, so that it is well equipped for swimming at an early age. The 
