LIFE HISTORIES OF NORTH AMERICAN PETRELS AND PELICANS. 221 



The measurements of 4-1: eggs, in various collections, average 77.G 

 by 47 millimeters; the eggs showing the four extremes measure 86.5 

 by 53.5, 70 by 47, and 80 by 37 millimeters. 



The period of incubation is variously given by different observei's 

 as from 39 to 44 days, and, as Mr. Gurney (1913) suggests, probably 

 42 clan's is about the average. Both sexes incubate. The absence of 

 any bare hatching space on the belly of the gannet is due to the 

 peculiar method in which the bird incubates. Mr. J. M. Campbell, 

 of the Bass Liglithouse, has given a very good account of this, which 

 Mr, Gurney (1913) quotes, as follows: 



Aligliting- on the eds'e of the nest, the liii'd shufiics on to the shallow depres- 

 sion, carefully adjusting the huge webs of both feet over the egg until it is 

 completely concealed from view. The body is then lowered over the feet until 

 the breast feathers but barely cover them, giving one the impression that thy 

 bird is not sitting sufficiently far forward on the nest. From this habit the 

 eggs, originally chalky white, soon become stained and discolored. 



Young. — The following account of the hatching process is also 

 taken from the writings of the same excellent observer : 



On the 5th of June the young solan was seen emerging from the shell 

 * * * The young bird, on making its exit from the egg, appeared to use at 

 first the little horny excrescence on the tip of the upper mandible for the 

 purpose of rupturing the inner membrane, mere pressure being afterwards suffi- 

 j:-ient to chip the shell. This is iuvarial)ly effected at the broad end, a little 

 deeper than one would cut a breakfast egg. The chipping was continued 

 slowly, bit by bit ; first a small portion of the tough membrane was ripped, then 

 the opposing shell pressed out. After a short rest, the bird wriggled a little 

 farther round — the bill always in view — and again renewed the attack, until 

 fully two-thirds of the circumference had been cut. The claws of one of the 

 feet now made their appearance over the lower edge of the fracture, and, by 

 dint of pressure of the whole body, the remaining third of the shell was 

 snapped, and out tumbled a black, sprawling object, helpless, blind, bare as the 

 palm of one's hand, and whining like a puppy dog. 



The very young gannet when first hatched is naked and livid 

 gray in color, an unattractive object, fat, shapeless, and helpless. 

 It is carefully brooded by its devoted parent, for it must be shielded 

 from the hot sun and protected against the rain and cold fogs 

 until, in the course of about three weeks, its protective coat of 

 soft, white down completely covers the body. It is well fed by 

 semidigested food from its parents' crop and increases rapidly in 

 size, until it equals or even exceeds the adult bird in weight. When 

 feeding a very young bird, the parent practically scoops the little 

 fellow into her mouth, but when larger the yoimgster is able to div8 

 into the cavernous throat and fish for himself. When old enough to 

 eat solid food the young bird is fed on fresh fish deposited near the 

 nest by its parents. AVhen about six weeks old the plumage appears 

 and by the end of September the flight stage is reached. Concern- 

 ing tliis interesting and critical period in the life of the young 



